CN102569295B - Bidirectional thyristor device based on capacitor-assisted trigger - Google Patents
Bidirectional thyristor device based on capacitor-assisted trigger Download PDFInfo
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- CN102569295B CN102569295B CN201210060501.XA CN201210060501A CN102569295B CN 102569295 B CN102569295 B CN 102569295B CN 201210060501 A CN201210060501 A CN 201210060501A CN 102569295 B CN102569295 B CN 102569295B
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- 230000002457 bidirectional effect Effects 0.000 title claims abstract description 8
- 239000003990 capacitor Substances 0.000 title abstract description 18
- 238000002347 injection Methods 0.000 claims abstract description 82
- 239000007924 injection Substances 0.000 claims abstract description 82
- 239000002184 metal Substances 0.000 claims abstract description 14
- 239000000758 substrate Substances 0.000 claims abstract description 8
- 230000015556 catabolic process Effects 0.000 abstract description 7
- 230000003068 static effect Effects 0.000 abstract description 7
- 238000005516 engineering process Methods 0.000 abstract description 2
- 229910052710 silicon Inorganic materials 0.000 description 22
- 239000010703 silicon Substances 0.000 description 22
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 21
- 238000000034 method Methods 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 230000003071 parasitic effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000002800 charge carrier Substances 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
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Abstract
The invention discloses a bidirectional thyristor device based on capacitor-assisted trigger, comprising a P substrate layer; a first N trap, a P trap and a second N trap arranged on the P substrate layer; a first N + active injection zone, a first P + active injection zone and a second N + active injection zone arranged on the first N trap; a third N + active injection zone, a second P + active injection zone and a fourth N + active injection zone arranged on the second N trap, wherein the third N + active injection zone is connected with a first capacitor, the other end of the first capacitor is connected with a first metal electrode, the second N + active injection zone is connected with a second capacitor and the other end of the second capacitor is connected with a second metal electrode. The thyristor device uses the capacitor as an auxiliary trigger unit, thus the device has adjustable and relatively lower forward and reverse breakdown voltage and the device can be suitable for on-chip ESD (electronic static discharge) protection under the deep sub-micron technology, particularly suitable for ESD protection application among a plurality of mixed voltage interface circuits or different power domains.
Description
Technical field
The invention belongs to integrated circuit electrostatic defending technical field, be specifically related to a kind of bidirectional triode thyristor device based on electric capacity auxiliary triggering.
Background technology
Natural static discharge (ESD) phenomenon has formed serious threat to the reliability of integrated circuit.In industrial quarters, the inefficacy 30% of integrated circuit (IC) products is all owing to suffering static discharge phenomenon caused, and more and more less process, and the probability that thinner gate oxide thickness all makes integrated circuit be subject to static discharge destruction increases greatly.Therefore the reliability of, improving integrated circuit electrostatic discharge protection has very important effect to the rate of finished products that improves product.
The pattern of static discharge phenomenon is divided into four kinds conventionally: HBM (human-body model), MM (machine discharge mode), CDM (assembly charging and discharging pattern) and electric field induction pattern (FIM).And the most common two kinds of static discharge patterns that are also industrial quarters product must pass through are HBM and MM.In the time there is static discharge, electric charge conventionally flows into and flows out from another pin from a pin of chip, and the electric current that now electrostatic charge produces is conventionally up to several amperes, and the voltage producing at electric charge input pin is up to even tens volts of several volts.If larger ESD electric current flows into inside chip, can cause the damage of inside chip, meanwhile, the high pressure producing at input pin also can cause internal components generation grid oxygen punch-through, thereby causes circuit malfunction.Therefore, in order to prevent that inside chip from damaged by ESD, to carry out effective ESD protection to each pin of chip, ESD electric current is released.
In the evolution of ESD protection, the devices such as diode, GGNMOS (the NMOS pipe of grid ground connection), SCR (controllable silicon) are used as ESD protective unit conventionally.For modern CMOS (complementary metal oxide semiconductors (CMOS)) integrated circuit, the input of chip output conventionally with input buffer stage the grid of output buffer stage or MOS device as input.Therefore, in the time there is esd event, ESD stress can be applied directly on grid oxygen, if ESD device opens not prompt enough or clamping voltage is too high, grid oxygen punch-through probably occurs, thereby chip is damaged.
Because unidirectional SCR structure has the low voltage that maintains, the features such as high current drain ability, so unidirectional SCR structure has very wide application in ESD protection.
Fig. 1 is the unidirectional SCR structure under a kind of CMOS technique, this unidirectional SCR trigger voltage is in one direction higher, and in another direction, be parasitic diode structure, trigger voltage is very low and non-adjustable, therefore, this structure is difficult to ESD protection in direct application sheet, especially can not be applied in the mixed-voltage domain interface circuit ESD protection that the two-way trigger voltage of ask for something is adjustable and lower.
Fig. 2 is the two-way SCR structure under a kind of CMOS technique, and this structure is compared unidirectional SCR structure, all has identical trigger voltage at both direction, but trigger voltage value is same too high and non-adjustable, under deep submicron process, is difficult to protect fragile grid oxygen.
Summary of the invention
For the existing above-mentioned technological deficiency of prior art, the invention discloses a kind of bidirectional triode thyristor device based on electric capacity auxiliary triggering, make controllable silicon on both direction, there is two-way adjustable and lower trigger voltage, can directly apply to the ESD protection of some the mixed-voltage interface circuits under deep submicron process.
A bidirectional triode thyristor device based on electric capacity auxiliary triggering, comprising:
P substrate layer;
On described P substrate layer, be from left to right provided with successively a N trap, P trap and the 2nd N trap, described P trap is connected with the 2nd N trap side by side with a N trap;
On a described N trap, be from left to right provided with side by side successively an active injection region of N+, an active injection region of P+ and the 2nd active injection region of N+; On the 2nd described N trap, be from left to right provided with side by side successively the 3rd active injection region of N+, the 2nd active injection region of P+ and the 4th active injection region of N+;
A described active injection region of N+ is connected by the first metal electrode with an active injection region of P+, and the 2nd described active injection region of P+ is connected by the second metal electrode with the 4th active injection region of N+;
The 3rd described active injection region of N+ is connected with the first electric capacity, and the other end of the first described electric capacity is connected with the first metal electrode; The 2nd described active injection region of N+ is connected with the second electric capacity, and the other end of the second described electric capacity is connected with the second metal electrode.
Shallow-trench isolation is passed through in a described active injection region of N+ and an active injection region of P+, an active injection region of P+ and the 2nd active injection region of N+, the 2nd active injection region of N+ and the 3rd active injection region of N+, the 3rd active injection region of N+ and the 2nd active injection region of P+ or the 2nd active injection region of P+ and the 4th active injection region of N+.
The equivalent electric circuit of described silicon-controlled device is made up of four resistance, three triodes and two electric capacity; Wherein, the emitter of the first triode is connected with one end of the first electric capacity with one end of the first resistance and forms the first electrode of silicon-controlled device, base stage is connected with the other end, one end of the second electric capacity and emitter or the collector electrode of the 3rd triode of the first resistance, and collector electrode is connected with one end of the 3rd resistance; The emitter of the second triode is connected with the other end of the second electric capacity with one end of the second resistance and forms the second electrode of silicon-controlled device, base stage is connected with the other end, the other end of the first electric capacity and collector electrode or the emitter of the 3rd triode of the second resistance, and collector electrode is connected with one end of the 4th resistance; The base stage of the 3rd triode is connected with the other end of the 4th resistance with the other end of the 3rd resistance.
Described the first triode and the second triode are positive-negative-positive triode, and the 3rd described triode is NPN type triode.
The first described triode is made up of described an active injection region of P+, a N trap and P trap; The second described triode is made up of described the 2nd active injection region of P+, the 2nd N trap and P trap; The 3rd described triode is made up of a N trap, the 2nd N trap and P trap; The first described resistance and the 3rd resistance are the dead resistance of a N trap; The second described resistance and the 4th resistance are the dead resistance of the 2nd N trap.
The protection voltage range of silicon-controlled device of the present invention can reach (1.2～5) V, and trigger voltage is (5～12) V.
Silicon-controlled device of the present invention utilizes electric capacity as auxiliary triggering unit, makes device have adjustable and lower trigger voltage, realizes the ESD protection of low trigger voltage; This silicon-controlled device has two-way forward and reverse puncture voltage simultaneously, makes device applicable to ESD protection on the sheet under deep submicron process, especially applicable to the ESD security application between some mixed-voltage interface circuits or different electrical power territory.
Brief description of the drawings
Fig. 1 is the structural representation of traditional one-way SCR device.
Fig. 2 is the structural representation of traditional double to silicon-controlled device.
Fig. 3 is the enforcement domain of silicon-controlled device of the present invention.
Fig. 4 is the generalized section of Fig. 3 along AA ' direction.
Fig. 5 is the equivalent circuit diagram of silicon-controlled device of the present invention.
Fig. 6 (a) is the ESD current drain path profile of silicon-controlled device of the present invention in the time that esd event betides A port.
Fig. 6 (b) is the ESD current drain path profile of silicon-controlled device of the present invention in the time that esd event betides K port.
Fig. 7 is the structural representation of silicon-controlled device of the present invention.
Fig. 8 is silicon-controlled device of the present invention and the traditional double current-voltage characteristic schematic diagram to silicon-controlled device.
Embodiment
In order more specifically to describe the present invention, below in conjunction with the drawings and the specific embodiments, technical scheme of the present invention and relative theory thereof are elaborated.
As shown in Figure 3 and Figure 4, a kind of bidirectional triode thyristor device based on electric capacity auxiliary triggering, comprising:
On P substrate layer 10, be from left to right provided with successively a N trap 21, P trap 23 and the 2nd N trap 22, P trap 23 is connected with the 2nd N trap 22 side by side with a N trap 21;
On the one N trap 21, be from left to right provided with side by side successively an active injection region 41 of N+, an active injection region 51 of P+ and the active injection region 42 of the 2nd N+; On the 2nd N trap 22, be from left to right provided with side by side successively the 3rd active injection region 43 of N+, the 2nd active injection region 52 of P+ and the active injection region 44 of the 4th N+;
The one active injection region 41 of N+ is connected by the first metal electrode 61 with an active injection region 51 of P+, and the 2nd active injection region 52 of P+ is connected by the second metal electrode 62 with the 4th active injection region 44 of N+;
The other end that the 3rd active injection region 43 of N+ is connected with the first capacitor C 1, the first capacitor C 1 is connected with the first metal electrode 61; The other end that the 2nd active injection region 42 of N+ is connected with the second capacitor C 2, the second capacitor C 2 is connected with the second metal electrode 62.
The active injection region 51 of the one active injection region 41 of N+ and a P+, an active injection region 51 of P+ and the active injection region 42 of the 2nd N+, the 2nd active injection region 42 of N+ and the active injection region 43 of the 3rd N+, the 3rd active injection region 43 of N+ and the active injection region 52 of the 2nd P+ and the active injection region 52 of the 2nd P+ and the active injection region 44 of the 4th N+ all isolate by shallow slot 3, in shallow slot 3, are filled with silica.
As shown in Figure 5, the equivalent electric circuit of present embodiment silicon-controlled device is made up of four resistance R 1～R4, three triode Q1～Q3 and two capacitor C 1～C2; Wherein, the emitter of the first triode Q1 is connected with one end of the first capacitor C 1 with one end of the first resistance R 1 and forms the A electrode of silicon-controlled device, base stage is connected with the other end, one end of the second capacitor C 2 and emitter or the collector electrode of the 3rd triode Q3 of the first resistance R 1, and collector electrode is connected with one end of the 3rd resistance R 3; The emitter of the second triode Q2 is connected with the other end of the second capacitor C 2 with one end of the second resistance R 2 and forms the K electrode of silicon-controlled device, base stage is connected with the other end, the other end of the first capacitor C 1 and collector electrode or the emitter of the 3rd triode Q3 of the second resistance R 2, and collector electrode is connected with one end of the 4th resistance R 4; The base stage of the 3rd triode Q3 is connected with the other end of the 4th resistance R 4 with the other end of the 3rd resistance R 3.
The first triode Q1 and the second triode Q2 are positive-negative-positive triode, and the 3rd triode Q3 is NPN type triode.
The first triode Q1 is made up of an active injection region 51 of P+, a N trap 21 and P trap 23; The second triode Q2 is made up of the 2nd active injection region 52 of P+, the 2nd N trap 22 and P trap 23; The 3rd triode Q3 is made up of a N trap 21, the 2nd N trap 22 and P trap 23; The first resistance R 1 and the 3rd resistance R 3 are the dead resistance of a N trap 21; The second resistance R 2 and the 4th resistance R 4 are the dead resistance of the 2nd N trap 22.
As shown in Fig. 6 (a) and Fig. 7, when esd event occurs in A end, and when K end ground connection, the reverse PN junction generation avalanche breakdown that the voltage that ESD electric current produces on A end can cause a N trap 21 and P trap 23 to form, when the pressure drop that produces in the first resistance R 1 of charge carrier producing when avalanche breakdown reaches the cut-in voltage (0.7V) of the forward diode that an active injection region 51 of P+ and a N trap 21 form, open in parasitic SCR path, and A terminal voltage is clamped to one compared with electronegative potential, ESD electric current now will be released by SCR path.Due to i=c*dv/dt, (i represents electric current, c represents electric capacity, dv represents the Sudden Changing Rate of electric capacity both end voltage) capacity effect exist, the reverse PN junction generation avalanche breakdown that the second capacitor C 2 can form prior to a N trap 21 and P trap 23, provide auxiliary current path by the 2nd active injection region 42 of N+ adding, make the first resistance R 1 produce enough pressure drops and allow the first triode Q1 more early open; Therefore trigger voltage is lower than not connecing in the situation of electric capacity.
As shown in Fig. 6 (b) and Fig. 7, when esd event occurs in K end, and when A end ground connection, the reverse PN junction generation avalanche breakdown that the voltage that ESD electric current produces on K end can cause the 2nd N trap 22 and P trap 23 to form, when the pressure drop that produces in the second resistance R 2 of charge carrier producing when avalanche breakdown reaches the cut-in voltage (0.7V) of the forward diode that the 2nd active injection region 52 of P+ and the 2nd N trap 22 form, open in parasitic SCR path, and K terminal voltage is clamped to one compared with electronegative potential, ESD electric current now will be released by SCR path.Simultaneously, also because capacity effect exists, the reverse PN junction generation avalanche breakdown that the first capacitor C 1 can form prior to the 2nd N trap 22 and P trap 23, provide auxiliary current path by the 3rd active injection region 43 of N+ adding, make the second resistance R 2 produce enough pressure drops and allow the second triode Q2 more early open; Therefore trigger voltage is lower than not connecing in the situation of electric capacity.
Shown in Fig. 8 present embodiment and traditional double held by A at ESD stress to silicon-controlled device to the current-voltage characteristic under K end, as can be seen from the figure traditional double is 34.5V to the trigger voltage of silicon-controlled device, and the trigger voltage of present embodiment only has 10.2V; Because two kinds of structures are two-way and symmetrical, when ESD stress is by K to A, the current-voltage characteristic curve symmetry of gained.Due to the existence of electric capacity (capacitance is 2.5PF), extra auxiliary current path is provided, parasitic triode is opened in advance, greatly reduce the trigger voltage of silicon-controlled device, and the size that can adjust by adjusting the capacitance of electric capacity two-way trigger voltage, is applicable to ESD protection on the sheet below deep-submicron.
Claims (1)
1. the bidirectional triode thyristor device based on electric capacity auxiliary triggering, is characterized in that, comprising:
P substrate layer (10);
On described P substrate layer (10), be from left to right provided with successively a N trap (21), P trap (23) and the 2nd N trap (22), described P trap (23) is connected with the 2nd N trap (22) side by side with a N trap (21);
On a described N trap (21), be from left to right provided with side by side successively an active injection region of N+ (41), an active injection region of P+ (51) and the 2nd active injection region of N+ (42); On the 2nd described N trap (22), be from left to right provided with side by side successively the 3rd active injection region of N+ (43), the 2nd active injection region of P+ (52) and the 4th active injection region of N+ (44);
A described active injection region of N+ (41) is connected by the first metal electrode (61) with an active injection region of P+ (51), and the 2nd described active injection region of P+ (52) is connected by the second metal electrode (62) with the 4th active injection region of N+ (44);
A described active injection region of N+ (41) isolates by shallow slot (3) with the 4th active injection region of N+ (44) with the 2nd active injection region of P+ (52) or the 2nd active injection region of P+ (52) with the 3rd active injection region of N+ (43), the 3rd active injection region of N+ (43) with an active injection region of P+ (51), an active injection region of P+ (51) and the 2nd active injection region of N+ (42), the 2nd active injection region of N+ (42);
The 3rd described active injection region of N+ (43) is connected with the first electric capacity, and the other end of the first described electric capacity is connected with the first metal electrode (61); The 2nd described active injection region of N+ (42) is connected with the second electric capacity, and the other end of the second described electric capacity is connected with the second metal electrode (62).
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| CN108461491B (en) * | 2018-03-21 | 2023-09-29 | 湖南静芯微电子技术有限公司 | Low-trigger bidirectional silicon controlled electrostatic protection device with high maintenance voltage |
| CN111725204B (en) * | 2019-07-18 | 2023-05-26 | 中国科学院上海微系统与信息技术研究所 | ESD protection device with bidirectional SCR structure |
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| US7786504B2 (en) * | 2008-03-20 | 2010-08-31 | Amazing Microelectronic Corp. | Bidirectional PNPN silicon-controlled rectifier |
| CN101281909B (en) * | 2008-05-28 | 2010-04-21 | 浙江大学 | NMOS pipe built-in bidirectional thyristor electrostatic protection device |
| CN102034811B (en) * | 2010-09-21 | 2012-07-04 | 电子科技大学 | Low-voltage SCR (Silicon Controlled Rectifier) structure for ESD (Electronic Static Discharge) protection of integrated circuit chip |
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