CA2070436A1 - Isotopically-pure carbon-12 or carbon-13 polycrystalline diamond possessing enhanced thermal conductivity - Google Patents
Isotopically-pure carbon-12 or carbon-13 polycrystalline diamond possessing enhanced thermal conductivityInfo
- Publication number
- CA2070436A1 CA2070436A1 CA002070436A CA2070436A CA2070436A1 CA 2070436 A1 CA2070436 A1 CA 2070436A1 CA 002070436 A CA002070436 A CA 002070436A CA 2070436 A CA2070436 A CA 2070436A CA 2070436 A1 CA2070436 A1 CA 2070436A1
- Authority
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- Canada
- Prior art keywords
- carbon
- polycrystalline diamond
- diamond
- isotopically
- thermal conductivity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000010432 diamond Substances 0.000 title claims abstract description 92
- 229910003460 diamond Inorganic materials 0.000 title claims abstract description 87
- OKTJSMMVPCPJKN-IGMARMGPSA-N Carbon-12 Chemical compound [12C] OKTJSMMVPCPJKN-IGMARMGPSA-N 0.000 title claims abstract description 23
- OKTJSMMVPCPJKN-OUBTZVSYSA-N Carbon-13 Chemical compound [13C] OKTJSMMVPCPJKN-OUBTZVSYSA-N 0.000 title claims abstract description 23
- 238000005229 chemical vapour deposition Methods 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 26
- 239000000758 substrate Substances 0.000 claims description 7
- 229910052582 BN Inorganic materials 0.000 claims description 3
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 claims description 3
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 3
- 229910000990 Ni alloy Inorganic materials 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 239000013078 crystal Substances 0.000 abstract description 6
- 230000000155 isotopic effect Effects 0.000 abstract description 6
- 239000012535 impurity Substances 0.000 abstract description 4
- 238000005245 sintering Methods 0.000 abstract description 3
- 230000003116 impacting effect Effects 0.000 abstract description 2
- 239000000463 material Substances 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 5
- CBQYNPHHHJTCJS-UHFFFAOYSA-N Alline Chemical compound C1=CC=C2C3(O)CCN(C)C3NC2=C1 CBQYNPHHHJTCJS-UHFFFAOYSA-N 0.000 description 4
- 239000010408 film Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 239000008246 gaseous mixture Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000001534 heteroepitaxy Methods 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- SYOKIDBDQMKNDQ-XWTIBIIYSA-N vildagliptin Chemical compound C1C(O)(C2)CC(C3)CC1CC32NCC(=O)N1CCC[C@H]1C#N SYOKIDBDQMKNDQ-XWTIBIIYSA-N 0.000 description 2
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 241001320695 Hermas Species 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 101100208721 Mus musculus Usp5 gene Proteins 0.000 description 1
- 241001274197 Scatophagus argus Species 0.000 description 1
- -1 acctylene Chemical compound 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000012217 deletion Methods 0.000 description 1
- 230000037430 deletion Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 229940099990 ogen Drugs 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 101150115956 slc25a26 gene Proteins 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
- C23C16/26—Deposition of carbon only
- C23C16/27—Diamond only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
- B01J3/06—Processes using ultra-high pressure, e.g. for the formation of diamonds; Apparatus therefor, e.g. moulds or dies
- B01J3/062—Processes using ultra-high pressure, e.g. for the formation of diamonds; Apparatus therefor, e.g. moulds or dies characterised by the composition of the materials to be processed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/0605—Composition of the material to be processed
- B01J2203/062—Diamond
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/0605—Composition of the material to be processed
- B01J2203/0645—Boronitrides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/065—Composition of the material produced
- B01J2203/0655—Diamond
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/065—Composition of the material produced
- B01J2203/066—Boronitrides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2203/00—Processes utilising sub- or super atmospheric pressure
- B01J2203/06—High pressure synthesis
- B01J2203/0675—Structural or physico-chemical features of the materials processed
- B01J2203/0685—Crystal sintering
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Carbon And Carbon Compounds (AREA)
- Chemical Vapour Deposition (AREA)
Abstract
DIAMOND POSSESSING ENHANCED THERMAL CONDUCTIVITY
ABSTRACT OF THE DISCLOSURE
Broadly, the present invention is directed to polycrystalline diamond of improved thermal conductivity. The novel polycrystalline diamond consists essentially of at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13. The inventive polycrystalline diamond is formed from at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13.
Single-crystal isotopically-pure carbon-12 and carbon-13 diamond are known to possess improved thermal conductivity. Polycrystalline diamond, however, possesses lowerthermal conductivity patterns deleteriously impacted by, for example, impurities, isotopic effects, and grain boundary scattering. In fact, grain boundary scattering would lead the skilled artisan to believe that the thermal conductivity of polycrystalline diamond would be substantially unaffected by the isotopic nature of the diamond itself. Unexpectedly, however, isotopic effects were discovered to predominate in impacting the thermal conductivity of polycrystalline diamond consisting essentially of isotopically-pure carbon-12 or carbon-13. This is true whether the isotopically-pure polycrystalline diamond is grown directly or whether individual isotopically-pure carbon-12 or carbon 13 diamond crystals are subjected to sintering for forming a polycrystalline structure, e.g. layer or compact, thereof.
ABSTRACT OF THE DISCLOSURE
Broadly, the present invention is directed to polycrystalline diamond of improved thermal conductivity. The novel polycrystalline diamond consists essentially of at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13. The inventive polycrystalline diamond is formed from at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13.
Single-crystal isotopically-pure carbon-12 and carbon-13 diamond are known to possess improved thermal conductivity. Polycrystalline diamond, however, possesses lowerthermal conductivity patterns deleteriously impacted by, for example, impurities, isotopic effects, and grain boundary scattering. In fact, grain boundary scattering would lead the skilled artisan to believe that the thermal conductivity of polycrystalline diamond would be substantially unaffected by the isotopic nature of the diamond itself. Unexpectedly, however, isotopic effects were discovered to predominate in impacting the thermal conductivity of polycrystalline diamond consisting essentially of isotopically-pure carbon-12 or carbon-13. This is true whether the isotopically-pure polycrystalline diamond is grown directly or whether individual isotopically-pure carbon-12 or carbon 13 diamond crystals are subjected to sintering for forming a polycrystalline structure, e.g. layer or compact, thereof.
Description
60S~0,~ 3 ~
7~_~LE
I:)IAMOND POS~ESS~JG ENHAN~D lHERMAL ~NDUCIlV17~
The present ~nven~on relates tO the preparadon of polycrystalline diarnond and more par~culaAy ~ polycrys~alline diamond possessing cnhanced Ihermal conductivity.
10High thennal conducdvity diamond, such a~ high quality sclected ~ype 1I natural diamond~ is charac~eriz~d by a vety high degree of purir" and is ~ o have a thcnr~l conduc~ity at 25-C (298-K) on thc order of aboul 21 wats/~n-K. Such high thcrrnal conduc~ mond is u~seful, fot e~tamplc, as a heat sink ma,~ , such as in the backing of semi-conduc~ Despi~ i~ high CQStS, type II natu~al d~nd has been employ~d as a 1$ heat sink material because it has the highest them~al conductivity of diamonds.
Conven~onally~ duccd high pressure/high tempeTanlre (HP/~I~) synthetic high quali~y, low nitrogen type Il diamonds can be produced with a simila~y high therrnal conduc~ivity.
For thc most pa~t, diamonds prepared by low-p~essu~e chemical vapor deposition (CVD) - p~cesscs are not single c~ys~al di~nond and have materially lower ~he~nal conductivities, 20 typically on thc aTder of 12 wuts/~n-K ~t about 300K (herein~ftcr sornetimes referred to , ~ Since di~wnd is usually an eleca-ical insulasor, f.e. ele~ic~ly non-conducting, heat is conduc~ed by phonons. Anything that shortens the phonorl mean free path ~i.e.
latdec ~,ribra~orl modes) de~cs thennal conducdYity. In 98% ~ nanlral diamonds (type 25 Ia), m~ogen impuri~e~ ~catter phonons. Thi~ reduces the mean f~c phonon pa~h and, thu3, shc ~mal conducti~ r, to nc~r 8 waats~/cm K In polys:~ystalline diamond ~ypical of that made by CVD p~ocesses, thae a~E muny dcfects, ~uch as, for example, nvins, grain botmda~ies, vacancie~, ~nd dislocations, ~hat reduce the phonon mean ~ree path. The ~'! t~ conducd~ r of CVD diamond is remarlkabl in one scnse in ~at it is ~bout 60% of 30 dlc th~mal conductivi~ of highly perfect diamond.
With ~e~pect to polycrystalline diamond (in fih3l, compact, or other form~, ~hennal cor~ucdvity is known tv bc af~ected by, ~r cxample, unp~des, isot~pic e~ s, and bound&~y sca~in& tO name jus~ a few fac~s. In fact, grain bound3ly scat~enng has bcen . ~ bclievcd to b~ do_n~nt in the lower ~hernul conduc~-~ity of polycrystalline diamond "
.
, ~ .
.'''~ , ' ~... .
~o~
compared to single crystal diamond. Enhancement of th~ thermal conducti~vity of polycrystaUine diamond, then, is a necd that yet exists in the art.
r~ad ~çrnent o~he Tnvention S Broadly, the presenl invention is directed tO polycrystalline diamond of improved therrnal conductivity. The novel polycrystalline diamond consists essentially of at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13. The inventive polycryslalline diamond is forrncd &~m at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13.
Single-crystal isotopically-pure carbon-12 and carbon-13 diamond are known to possess improved thermal conductivity. Polycrystalline diamond, however, possesses thennal conducdvity patterns deleteriously irnpacted by, for example, impurities, isotopic effects, and grain boundary scattering. In fact, grain boundaly scaKering would lead ~he skilled artisan to believe that the thennal conducdvity of polycrystalline diamond would bs subs~antially unaffected by the isotopic naturc of the diamond itself. Unexpectedly, however, isotopic effects were discovered to predominate in impacting the therrnal conduc~vity of polycrystalline diamond consisting essentially of isotopically-pure carbon-12 and carbon-13. This is true whether the isotopically-pure polycrystalline diamond is grown directly or wheth individual iso~opically-pure carbon-12 or carbon 13 diamond crystals are subjected to sintering for ~orming a polycrystalline structure, e.g. Iayer or compact, thercof.
Detailed lXsOE~Qf the Invçn~Qn Heat conductivity in diamond is qui~e complicated, especially considering the parallel and se~ies paths that it çan take. It should be understood that theorics on heat 2S conducdvi~ in di~mond, then, are inconsistent in the li~erature and, likely, are incomplete.
Thus, much of ~he the~y expounded he~in should b¢ intelpret~ accordingly. Rcgsrdless of ~ the~ic~ a~poul!ded herein, synthesis of polycrystalline carbon-12 and carbon-13 has been achicve~ and the unexpectcd thermal conduc~ confimled.
The dcscription that follows is directed par~cularly to 12C diamond, but it holds equally tr~e for 13C diamond as well. Since diamond is an insulator, hea~ is conducted by phonon~ ~qua~on I, ~low, sets fonh the th~nal conduc~Yity of polycsystalline diamond in ~nn~ of ~hG ~pecific heat (C), phonon veloci~ , and fnean f~ec path of phonons O-(~) K = (113)CV~, or K
It has bcen shown prcviously that both the specific heat and the phonon vel~i~ (the sound vclocity) are thc samc in high quality diamosld arld diamond made by chemical vapor deposidon (CVD) tcchniques. Consequently, all th~ Yariatisn in thermal conductivity .
7~_~LE
I:)IAMOND POS~ESS~JG ENHAN~D lHERMAL ~NDUCIlV17~
The present ~nven~on relates tO the preparadon of polycrystalline diarnond and more par~culaAy ~ polycrys~alline diamond possessing cnhanced Ihermal conductivity.
10High thennal conducdvity diamond, such a~ high quality sclected ~ype 1I natural diamond~ is charac~eriz~d by a vety high degree of purir" and is ~ o have a thcnr~l conduc~ity at 25-C (298-K) on thc order of aboul 21 wats/~n-K. Such high thcrrnal conduc~ mond is u~seful, fot e~tamplc, as a heat sink ma,~ , such as in the backing of semi-conduc~ Despi~ i~ high CQStS, type II natu~al d~nd has been employ~d as a 1$ heat sink material because it has the highest them~al conductivity of diamonds.
Conven~onally~ duccd high pressure/high tempeTanlre (HP/~I~) synthetic high quali~y, low nitrogen type Il diamonds can be produced with a simila~y high therrnal conduc~ivity.
For thc most pa~t, diamonds prepared by low-p~essu~e chemical vapor deposition (CVD) - p~cesscs are not single c~ys~al di~nond and have materially lower ~he~nal conductivities, 20 typically on thc aTder of 12 wuts/~n-K ~t about 300K (herein~ftcr sornetimes referred to , ~ Since di~wnd is usually an eleca-ical insulasor, f.e. ele~ic~ly non-conducting, heat is conduc~ed by phonons. Anything that shortens the phonorl mean free path ~i.e.
latdec ~,ribra~orl modes) de~cs thennal conducdYity. In 98% ~ nanlral diamonds (type 25 Ia), m~ogen impuri~e~ ~catter phonons. Thi~ reduces the mean f~c phonon pa~h and, thu3, shc ~mal conducti~ r, to nc~r 8 waats~/cm K In polys:~ystalline diamond ~ypical of that made by CVD p~ocesses, thae a~E muny dcfects, ~uch as, for example, nvins, grain botmda~ies, vacancie~, ~nd dislocations, ~hat reduce the phonon mean ~ree path. The ~'! t~ conducd~ r of CVD diamond is remarlkabl in one scnse in ~at it is ~bout 60% of 30 dlc th~mal conductivi~ of highly perfect diamond.
With ~e~pect to polycrystalline diamond (in fih3l, compact, or other form~, ~hennal cor~ucdvity is known tv bc af~ected by, ~r cxample, unp~des, isot~pic e~ s, and bound&~y sca~in& tO name jus~ a few fac~s. In fact, grain bound3ly scat~enng has bcen . ~ bclievcd to b~ do_n~nt in the lower ~hernul conduc~-~ity of polycrystalline diamond "
.
, ~ .
.'''~ , ' ~... .
~o~
compared to single crystal diamond. Enhancement of th~ thermal conducti~vity of polycrystaUine diamond, then, is a necd that yet exists in the art.
r~ad ~çrnent o~he Tnvention S Broadly, the presenl invention is directed tO polycrystalline diamond of improved therrnal conductivity. The novel polycrystalline diamond consists essentially of at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13. The inventive polycryslalline diamond is forrncd &~m at least 99.5 wt-% isotopically-pure carbon-12 or carbon-13.
Single-crystal isotopically-pure carbon-12 and carbon-13 diamond are known to possess improved thermal conductivity. Polycrystalline diamond, however, possesses thennal conducdvity patterns deleteriously irnpacted by, for example, impurities, isotopic effects, and grain boundary scattering. In fact, grain boundaly scaKering would lead ~he skilled artisan to believe that the thennal conducdvity of polycrystalline diamond would bs subs~antially unaffected by the isotopic naturc of the diamond itself. Unexpectedly, however, isotopic effects were discovered to predominate in impacting the therrnal conduc~vity of polycrystalline diamond consisting essentially of isotopically-pure carbon-12 and carbon-13. This is true whether the isotopically-pure polycrystalline diamond is grown directly or wheth individual iso~opically-pure carbon-12 or carbon 13 diamond crystals are subjected to sintering for ~orming a polycrystalline structure, e.g. Iayer or compact, thercof.
Detailed lXsOE~Qf the Invçn~Qn Heat conductivity in diamond is qui~e complicated, especially considering the parallel and se~ies paths that it çan take. It should be understood that theorics on heat 2S conducdvi~ in di~mond, then, are inconsistent in the li~erature and, likely, are incomplete.
Thus, much of ~he the~y expounded he~in should b¢ intelpret~ accordingly. Rcgsrdless of ~ the~ic~ a~poul!ded herein, synthesis of polycrystalline carbon-12 and carbon-13 has been achicve~ and the unexpectcd thermal conduc~ confimled.
The dcscription that follows is directed par~cularly to 12C diamond, but it holds equally tr~e for 13C diamond as well. Since diamond is an insulator, hea~ is conducted by phonon~ ~qua~on I, ~low, sets fonh the th~nal conduc~Yity of polycsystalline diamond in ~nn~ of ~hG ~pecific heat (C), phonon veloci~ , and fnean f~ec path of phonons O-(~) K = (113)CV~, or K
It has bcen shown prcviously that both the specific heat and the phonon vel~i~ (the sound vclocity) are thc samc in high quality diamosld arld diamond made by chemical vapor deposidon (CVD) tcchniques. Consequently, all th~ Yariatisn in thermal conductivity .
-2~
60S~7~
between different grades of diamond occurs because of diffetences in the mean free path of phonons in dif~rens grades of diamond. The mean free path of a phonon is given by the following ~quation:
S (II) 11~ phonon-phonon + IJ~ grain-boundaries + 1/~ disloca~ions +
1/~ vacancies ~ impurities + 1/~ isotopes + ......
wherc, scattering caused by phonon-phonon interactions, grain boundaries, dislocations, vacancies, impurities, and isotopes arc included explicitly, while other possible scattering centcFs (e.g., small voids) are repsescnted by ".. ".
Estimates of so~e of thc phonon mcan frce path length ~om themlal diffusivity data of natu~al isotope abundance high quality diamorld and isotopically pure high quali~
` ~ diamund can be made. The avc~age phonon veioeity at room ~empcrature in diamond is equal to the sound velocity of 1.38 x 10~ cm/sec. The specific heat of diamond at room temperatu1e is reported to be 6.195 joules/g. For isotopically-purc high quality diamond, the phonon mean ~ee pa~h is limited principally by a phonon-phonon scattering. From equa~on I, we find that A phonon-phonon is 0.17 microns.
For natural isotopc abundance high quality diamond, thc phonon mean free path isdetermined by both phonon-phonon and phonon-isotope scattering, and is equal to 0.09 microns. From shis value an~ equation 11, W5 can denve the mean free path of isotope scattering ~ isotopes to be 0.19 microns.
For polyc~ystalline CVD diamond, addilional phonon scattering centers come into play and the themlal conducd~i~ is decneased to approxima~ely 12 wa~ts/cm-'K. which gives a phonon mean fiec path of 0.05 micr~ns. Sevcral observa~ons about the magnitude 2S of this phonon mean free path shoold be made. Firs~, elimination of scattering centers, which are much more widcly spaced than 0.05 microns, will not affcct the therrnal conduc~vi~q acco~ding to equa~on n. Thus, elin~ination of grain boundanes in CVD or othcr polycrys~alline diamond material having a gTain size o~ 10 mic~ns, for example, will only increase ~c ~herma~ eonduc~ r by Q596.
Secondly, although ~limination of grain boundaric~ by using epitaxial growth on diamond o~ hete~cpita~dal growth on a ~oreign substrate will not affect the therrnal conducti~fity, such growth may lead to a lower concen~a~on of dislocations by starting with perfect seed cFystals and ~he~eby increase the thcmlal conduc~ivity. From etch pitch studics it has been estimated that the dislocation density in typical CVD diamond material excecds 108 disloca~ions/cm2. Thc phonon mean free path ftom scattering off of disloca~ons should be less than I micron. Elin~inadon of all dislocations should increase the thennal conduc~vity by grealer than 5%.
"
60S~7~
between different grades of diamond occurs because of diffetences in the mean free path of phonons in dif~rens grades of diamond. The mean free path of a phonon is given by the following ~quation:
S (II) 11~ phonon-phonon + IJ~ grain-boundaries + 1/~ disloca~ions +
1/~ vacancies ~ impurities + 1/~ isotopes + ......
wherc, scattering caused by phonon-phonon interactions, grain boundaries, dislocations, vacancies, impurities, and isotopes arc included explicitly, while other possible scattering centcFs (e.g., small voids) are repsescnted by ".. ".
Estimates of so~e of thc phonon mcan frce path length ~om themlal diffusivity data of natu~al isotope abundance high quality diamorld and isotopically pure high quali~
` ~ diamund can be made. The avc~age phonon veioeity at room ~empcrature in diamond is equal to the sound velocity of 1.38 x 10~ cm/sec. The specific heat of diamond at room temperatu1e is reported to be 6.195 joules/g. For isotopically-purc high quality diamond, the phonon mean ~ee pa~h is limited principally by a phonon-phonon scattering. From equa~on I, we find that A phonon-phonon is 0.17 microns.
For natural isotopc abundance high quality diamond, thc phonon mean free path isdetermined by both phonon-phonon and phonon-isotope scattering, and is equal to 0.09 microns. From shis value an~ equation 11, W5 can denve the mean free path of isotope scattering ~ isotopes to be 0.19 microns.
For polyc~ystalline CVD diamond, addilional phonon scattering centers come into play and the themlal conducd~i~ is decneased to approxima~ely 12 wa~ts/cm-'K. which gives a phonon mean fiec path of 0.05 micr~ns. Sevcral observa~ons about the magnitude 2S of this phonon mean free path shoold be made. Firs~, elimination of scattering centers, which are much more widcly spaced than 0.05 microns, will not affcct the therrnal conduc~vi~q acco~ding to equa~on n. Thus, elin~ination of grain boundanes in CVD or othcr polycrys~alline diamond material having a gTain size o~ 10 mic~ns, for example, will only increase ~c ~herma~ eonduc~ r by Q596.
Secondly, although ~limination of grain boundaric~ by using epitaxial growth on diamond o~ hete~cpita~dal growth on a ~oreign substrate will not affect the therrnal conducti~fity, such growth may lead to a lower concen~a~on of dislocations by starting with perfect seed cFystals and ~he~eby increase the thcmlal conduc~ivity. From etch pitch studics it has been estimated that the dislocation density in typical CVD diamond material excecds 108 disloca~ions/cm2. Thc phonon mean free path ftom scattering off of disloca~ons should be less than I micron. Elin~inadon of all dislocations should increase the thennal conduc~vity by grealer than 5%.
"
,, , ' , ' ,~ 60æ~
:` ~
A reduction in the numbers of grain boundaries can be achieved through the control of nucleation during the initial stages of diamond growth. This can be accomplished by a vanety of means. Heteroepitaxy would allow single crystal films, if successful. Even if polycrystalline material was forrned, it would have fewer grain boundaries than standard 5 CVD diamond grown on Si, Mo, etc. Suitable substrates for heteroepitaxy would be Ni, Cu/Ni alloys, CBN (cubic boron nitride), ana CBN films grown epitaxially on Si. Another approach is to seed the substrate with diamonds. Using CVD diamond to grow homoepitaxially, it should be possible to control the orientation grain boundaries of the film. Reducing the grain boundaries and the dislocation density would eliminate phonon 10 scattering and increase the thermal conducdvity of the resulting film.
Probably the largest scatter of phonons and CVD diamond are vacancies and vacancy clusters. Because CVD diamond is deposited at a temperature of about 900'C, which is less than 1/4 the melting tempcrature of diamond, there is not much solid-state diffusion during deposition. This lack of defect mobility causes a large amount of atomic ,~ 15 defects, such as vacancies, to be frozen during growth. Current CVD technology, however, militatcs against improving this condition.
One scatteling center that is easily removable from CVD diamond are carbon-13 isotopes when mak;ng isotopically-pure carbon-12 (and carbon-12 isotopes when making isotopically-pur~ carbon-13). Knowing the mean free palh of isotope scattering, equation 20 II can be used to esdmate the change in thermal conductivity that can be expec~ed by eliminating uowanted isotopes fiom conven~ional CVD material with a therrnal conductivity ~' of 12 watts/cm--K. Deletion of ~ isotopes equals 0.19 microns in equation II and - substitution of ~e enhanced A in equation I shows that the thermal conductivity of CVD
diarnond should increass &om 12 to 15 watts/cm--K when it is made of isotopically pure 25 carbon-12. Th~ thermal conductivity for isotopically-pure car~on-13 similarly should increase to a~und lS watts/cm--K.
Lascr flash diffusivity IR detection sys~em dasa was generated fiom about 0.5 mmthick dislcs of CVD diamond which was greater than 99.5 wt-% isotopically pure carbon-12. Onc side of thc disk was blackened and a laser polse irnpac~ed the~eon. Diffusivity or 30 the time rabe of temperature decay, was detectcd by an inf~ared detector on the reve~e side of the samplo. The measurement was made at room tempera~ure, l~iZ., 2S-C. A natural abundance isotopc sample also was tested. The natural isotope sarnple testcd at 8 watts/cm-C while the iso~spically pure samplc tested at 12 watts/cm--C. Thus, the thermal conductivity of polyclystalline isotopically pure carbon-13 material unexpectedly has a 35 much higher th~mal conductivity than the polycTystalline diamond made from natural - abundance isotopes. The value of the the~mal conductivi~ can only be improved by paying atten~on to dislocations, vacancies, vacancy c3usters, and like factors that tend to depress the th~nal conductivity of the polycrystalline diamond pieces. Controlling grain.~ .
, .
, ' ' ~Q7~
boundanes also is important as obvious loss of therrnal conductivit,Y is expenenced, though not ncarly to thc degree with isotopically pure polycrystallinc diamond than with natural isotopc abundant polycrystalline diarnond.
As noted above, the isotopically-pure polycrystalline diamond can be grown by SCVD ~echniques, or can be grown by high pressure/high temperature (HP/HT) techniques including growing the polycrystallinc diam~nd directly, or growing the polycrystalline diarnond and then sintering the diamond to form an appropriate piece. Though HP/HT
techniques are well known in the art, reference to the following patents provides details on such processing conditions: U.S. Pat. No. 3,141,746; 3,381,~28; 3,609,818; 3,745,623;
103,831,428; and 3,850,591, Ihe disclosures of which are expressly incorporated herein by referencc.
With rcspect to conventional CVD processes useful in the present invention, hydr~carbon/hydrogen gaseous mixtures are fed into a CVD reactor as an initial step.
Hydrocarbon sources can includç the methane series gases, e.g. methane, ethane, propane;
15unsanlrated hydroearbons, e.g. ethylene, acctylene, cyclohexene, and benzene; and the likc. Methane, however, is preferred. Use of either carbon-12 or carbon-13 for these hydrocarbon sour~es is made in accordance wilh the precepls of thc present invendon. The mol~r ratio of hydTocarbon to hydrogen broadly ~anges &om about 1:10 to about 1:1,000 vith about 1:100 being prefe~d. l~is gaseous mixture opdonally may be diluted with an 20inert gas, e.g. argon. The gaseous mixture is at least pardally deeomposed thermally by one of sevcral tecbniques known in thc ar~. One of thesc techniques involves the use of a hot filament which normally is fo~mcd of tungsten, molybdenum, tantalum, or alloys - thereof. U.S. Pat. No. 4,707,384 illustrates this process.
The gaseou3 mixturc partial decomposition also can be conducted with the 25assistancc of d.c. discharge or radio frequency electromagnetie radiadon to generate a plasma, such æ proposed in U.S. Pats. Nos. ~,749,587, 4,767,608, ~nd 4,830,702; and U.S. Pat. No. 4,434,188 with respect to use of n~icrowaves. Thc substrate may bebombarded with cl¢c~rons dunng the CVD dccomposition p~cess in a~cordance with U.S.
Pat. NQ 4,740,263.
3ûRegardless of the particular method used in generadrlg thc pamally decomposed gaseou~ mihcture, the substratc is maintained at an clcvated CVD diamond-folrning ten~c~at~ which typieally ranges from abou~ 500 to 1100~ C and ps~ferably in the rangc of about 850 to 950J C where diamond growth is at its highes; rate in order to minimize grain size. Pr~ssu~es in thc range of firom aboult 0.01 to 1000 Tog, advantageously about 35100-800 Tolr, are taught in thc art, with reduced pressL~ being prefe~ed. DetaiJs on CVD
,! processcs additionally can be reviewed by referencc to Angus, e~ al., "Low-Pressure, MetastaUe G~ h of Diamond and 'Diamondlike' Phases", 5cfencc, ~ol. 241, pages 913-921 (August 19, 1988); and 13achmann, e~ al., "Dia~nond Thin Films", Chemical and 6 OSD~
Engineering New3, pages 24-39 (May 15, 1989). The disclosurcs of all citations hercin a~e expressly inco~orated herein by referencc.
`:
"
.
',' ~, ; ' ~'.
,^-` ' .
i..
d ,. .
.`
'' 'j'~' ' ,' ' - .
.r ... .
' Y~ ' ' , :
, ., . ' , ,
:` ~
A reduction in the numbers of grain boundaries can be achieved through the control of nucleation during the initial stages of diamond growth. This can be accomplished by a vanety of means. Heteroepitaxy would allow single crystal films, if successful. Even if polycrystalline material was forrned, it would have fewer grain boundaries than standard 5 CVD diamond grown on Si, Mo, etc. Suitable substrates for heteroepitaxy would be Ni, Cu/Ni alloys, CBN (cubic boron nitride), ana CBN films grown epitaxially on Si. Another approach is to seed the substrate with diamonds. Using CVD diamond to grow homoepitaxially, it should be possible to control the orientation grain boundaries of the film. Reducing the grain boundaries and the dislocation density would eliminate phonon 10 scattering and increase the thermal conducdvity of the resulting film.
Probably the largest scatter of phonons and CVD diamond are vacancies and vacancy clusters. Because CVD diamond is deposited at a temperature of about 900'C, which is less than 1/4 the melting tempcrature of diamond, there is not much solid-state diffusion during deposition. This lack of defect mobility causes a large amount of atomic ,~ 15 defects, such as vacancies, to be frozen during growth. Current CVD technology, however, militatcs against improving this condition.
One scatteling center that is easily removable from CVD diamond are carbon-13 isotopes when mak;ng isotopically-pure carbon-12 (and carbon-12 isotopes when making isotopically-pur~ carbon-13). Knowing the mean free palh of isotope scattering, equation 20 II can be used to esdmate the change in thermal conductivity that can be expec~ed by eliminating uowanted isotopes fiom conven~ional CVD material with a therrnal conductivity ~' of 12 watts/cm--K. Deletion of ~ isotopes equals 0.19 microns in equation II and - substitution of ~e enhanced A in equation I shows that the thermal conductivity of CVD
diarnond should increass &om 12 to 15 watts/cm--K when it is made of isotopically pure 25 carbon-12. Th~ thermal conductivity for isotopically-pure car~on-13 similarly should increase to a~und lS watts/cm--K.
Lascr flash diffusivity IR detection sys~em dasa was generated fiom about 0.5 mmthick dislcs of CVD diamond which was greater than 99.5 wt-% isotopically pure carbon-12. Onc side of thc disk was blackened and a laser polse irnpac~ed the~eon. Diffusivity or 30 the time rabe of temperature decay, was detectcd by an inf~ared detector on the reve~e side of the samplo. The measurement was made at room tempera~ure, l~iZ., 2S-C. A natural abundance isotopc sample also was tested. The natural isotope sarnple testcd at 8 watts/cm-C while the iso~spically pure samplc tested at 12 watts/cm--C. Thus, the thermal conductivity of polyclystalline isotopically pure carbon-13 material unexpectedly has a 35 much higher th~mal conductivity than the polycTystalline diamond made from natural - abundance isotopes. The value of the the~mal conductivi~ can only be improved by paying atten~on to dislocations, vacancies, vacancy c3usters, and like factors that tend to depress the th~nal conductivity of the polycrystalline diamond pieces. Controlling grain.~ .
, .
, ' ' ~Q7~
boundanes also is important as obvious loss of therrnal conductivit,Y is expenenced, though not ncarly to thc degree with isotopically pure polycrystallinc diamond than with natural isotopc abundant polycrystalline diarnond.
As noted above, the isotopically-pure polycrystalline diamond can be grown by SCVD ~echniques, or can be grown by high pressure/high temperature (HP/HT) techniques including growing the polycrystallinc diam~nd directly, or growing the polycrystalline diarnond and then sintering the diamond to form an appropriate piece. Though HP/HT
techniques are well known in the art, reference to the following patents provides details on such processing conditions: U.S. Pat. No. 3,141,746; 3,381,~28; 3,609,818; 3,745,623;
103,831,428; and 3,850,591, Ihe disclosures of which are expressly incorporated herein by referencc.
With rcspect to conventional CVD processes useful in the present invention, hydr~carbon/hydrogen gaseous mixtures are fed into a CVD reactor as an initial step.
Hydrocarbon sources can includç the methane series gases, e.g. methane, ethane, propane;
15unsanlrated hydroearbons, e.g. ethylene, acctylene, cyclohexene, and benzene; and the likc. Methane, however, is preferred. Use of either carbon-12 or carbon-13 for these hydrocarbon sour~es is made in accordance wilh the precepls of thc present invendon. The mol~r ratio of hydTocarbon to hydrogen broadly ~anges &om about 1:10 to about 1:1,000 vith about 1:100 being prefe~d. l~is gaseous mixture opdonally may be diluted with an 20inert gas, e.g. argon. The gaseous mixture is at least pardally deeomposed thermally by one of sevcral tecbniques known in thc ar~. One of thesc techniques involves the use of a hot filament which normally is fo~mcd of tungsten, molybdenum, tantalum, or alloys - thereof. U.S. Pat. No. 4,707,384 illustrates this process.
The gaseou3 mixturc partial decomposition also can be conducted with the 25assistancc of d.c. discharge or radio frequency electromagnetie radiadon to generate a plasma, such æ proposed in U.S. Pats. Nos. ~,749,587, 4,767,608, ~nd 4,830,702; and U.S. Pat. No. 4,434,188 with respect to use of n~icrowaves. Thc substrate may bebombarded with cl¢c~rons dunng the CVD dccomposition p~cess in a~cordance with U.S.
Pat. NQ 4,740,263.
3ûRegardless of the particular method used in generadrlg thc pamally decomposed gaseou~ mihcture, the substratc is maintained at an clcvated CVD diamond-folrning ten~c~at~ which typieally ranges from abou~ 500 to 1100~ C and ps~ferably in the rangc of about 850 to 950J C where diamond growth is at its highes; rate in order to minimize grain size. Pr~ssu~es in thc range of firom aboult 0.01 to 1000 Tog, advantageously about 35100-800 Tolr, are taught in thc art, with reduced pressL~ being prefe~ed. DetaiJs on CVD
,! processcs additionally can be reviewed by referencc to Angus, e~ al., "Low-Pressure, MetastaUe G~ h of Diamond and 'Diamondlike' Phases", 5cfencc, ~ol. 241, pages 913-921 (August 19, 1988); and 13achmann, e~ al., "Dia~nond Thin Films", Chemical and 6 OSD~
Engineering New3, pages 24-39 (May 15, 1989). The disclosurcs of all citations hercin a~e expressly inco~orated herein by referencc.
`:
"
.
',' ~, ; ' ~'.
,^-` ' .
i..
d ,. .
.`
'' 'j'~' ' ,' ' - .
.r ... .
' Y~ ' ' , :
, ., . ' , ,
Claims (21)
1. Polycrystalline diamond of improved thermal conductivity which consists essentially of at least 99.5 wt-% isotopically-pure carbon-13.
2. The polycrystalline diamond of claim 1 which is made by chemical vapor deposition (CVD) techniques.
3. Thc polycrystalline diamond of claim 1 which is made high pressure/high tempaature (HP/HT) techniques.
4. The polycrystalline diamond of claim 1 which is one crystallite thick.
5 A method for improving the thermal conductivity of polycrystalline diamond which consists essentially of forming said polycrystalline diamond of at least 99.5 wt-%
isotopically pure carbon-13.
isotopically pure carbon-13.
6. The method of claim 5 wherein said carbon-13 polycrystalline diamond is made by chemical vapor deposition (CVD) techniques.
7. The method of claim 5 wherein said carbon-13 polycrystalline diamond is made by high pressure/high temperature (HP/HT) techniques.
8. The method of claim 5 wherein said carbon-13 polycrystalline diamond is formed to be one crystallite thick.
9. The method of claim 6 wherein said carbon-13 polycrystalline diamond is grown on a substrate selected from Ni, Cu/Ni alloys, and cubic boron nitride.
10 The method of claim 6 wherein said carbon-13 polycrystalline diamond is grown on a substrate seed with diamond.
11. Polycrystalline diamond of improved thermal conductivity which consists essentially at least 99.5 wt-% isotopically-pure carbon-12.
12. The polycrystalline diamond of claim 11 which is made by chemical vapor deposition (CVD) techniques.
13. The polycrystalline diamond of claim 11 which is made high pressure/high temperature (HP/HT) techniques.
14. The polycrystalline diamond of claim 11 which is one crystallite thick.
15. A method for improving the thermal conductivity of polycrystalline diamond which consists essentially of forming said polycrystalline diamond of at least 99.5 wt-%
isotopically-pule carbon-12.
isotopically-pule carbon-12.
16. The method of claim 15 wherein said carbon-12 polycrystalline diamond is made by chemical vapor deposition (CVD) techniques.
17. The method of claim 15 wherein said carbon-12 polycrystalline diamond is made by high pressure/high temperature (HP/HT) techniques.
18. The method of claim 15 wherein said polycrystalline diamond is formed to be one crystallite thick.
19. The method of claim 16 wherein said carbon-12 polycrystalline diamond is grown on a substrate selectcd from Ni, Cu/Ni alloys, and cubic boron nitride.
20 The method of claim 16 wherein said carbon-12 polycrystalline diamond is grown on a substrae seed with diamond.
21. The invention as defined in any of the preceding claims including any further features of novelty disclosed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72701691A | 1991-07-08 | 1991-07-08 | |
| US727,016 | 1991-07-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2070436A1 true CA2070436A1 (en) | 1993-01-09 |
Family
ID=24920984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002070436A Abandoned CA2070436A1 (en) | 1991-07-08 | 1992-06-04 | Isotopically-pure carbon-12 or carbon-13 polycrystalline diamond possessing enhanced thermal conductivity |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH05194089A (en) |
| CA (1) | CA2070436A1 (en) |
| GB (1) | GB2257427B (en) |
| ZA (1) | ZA924614B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11100297A (en) * | 1997-08-01 | 1999-04-13 | Tokyo Gas Co Ltd | Isotopic diamond doped with boron and its production |
| JP5891634B2 (en) * | 2011-07-28 | 2016-03-23 | 住友電気工業株式会社 | Polycrystalline diamond and method for producing the same |
| JP5891635B2 (en) * | 2011-07-28 | 2016-03-23 | 住友電気工業株式会社 | Polycrystalline diamond and method for producing the same |
| JP5891636B2 (en) * | 2011-07-28 | 2016-03-23 | 住友電気工業株式会社 | Polycrystalline diamond and method for producing the same |
| WO2013015347A1 (en) * | 2011-07-28 | 2013-01-31 | 住友電気工業株式会社 | Polycrystalline diamond and manufacturing method therefor |
| JP6772711B2 (en) * | 2016-09-20 | 2020-10-21 | 住友電気工業株式会社 | Semiconductor laminated structures and semiconductor devices |
| EP4353677A4 (en) * | 2021-06-11 | 2024-07-31 | Sumitomo Electric Hardmetal Corp | Composite polycrystal and tool with composite polycrystal |
| US20240199430A1 (en) * | 2021-06-11 | 2024-06-20 | Sumitomo Electric Hardmetal Corp. | Diamond polycrystalline body, and tool comprising diamond polycrystalline body |
| JP7180054B1 (en) * | 2021-06-11 | 2022-11-30 | 住友電工ハードメタル株式会社 | Polycrystalline diamond and tool comprising polycrystalline diamond |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0206820A3 (en) * | 1985-06-27 | 1987-10-28 | De Beers Industrial Diamond Division (Proprietary) Limited | Diamond synthesis |
| GB8903793D0 (en) * | 1989-02-20 | 1989-04-05 | Plessey Co Plc | Diamond synthesis |
-
1992
- 1992-06-04 CA CA002070436A patent/CA2070436A1/en not_active Abandoned
- 1992-06-23 ZA ZA924614A patent/ZA924614B/en unknown
- 1992-07-07 JP JP4179494A patent/JPH05194089A/en not_active Withdrawn
- 1992-07-07 GB GB9214434A patent/GB2257427B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ZA924614B (en) | 1993-12-23 |
| JPH05194089A (en) | 1993-08-03 |
| GB2257427B (en) | 1995-05-24 |
| GB2257427A (en) | 1993-01-13 |
| GB9214434D0 (en) | 1992-08-19 |
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