CN1243256A - Optical waveguide and mfg. method thereof - Google Patents
Optical waveguide and mfg. method thereof Download PDFInfo
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- CN1243256A CN1243256A CN 99110515 CN99110515A CN1243256A CN 1243256 A CN1243256 A CN 1243256A CN 99110515 CN99110515 CN 99110515 CN 99110515 A CN99110515 A CN 99110515A CN 1243256 A CN1243256 A CN 1243256A
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Abstract
Disclosed are a method of manufacturing an optical waveguide including core portions having a small surface roughness and also having highly accurately rectangular shapes without requiring a large number of the manufacturing steps, and an optical waveguide with a small propagation loss of light. The optical waveguide includes a substrate; a lower clad layer formed on the substrate; core portions formed on the lower clad layer; and an upper clad layer formed to cover the lower clad layer and the core portions; wherein the substrate is made from a material which is transparent to light having a specific wavelength, and the core portions are made from a material which is hardened by irradiation of the light having the specific wavelength. If the light having the specific wavelength is ultraviolet light, the core portions are made from an ultraviolet hardening-type material hardened by irradiation of ultraviolet light and the substrate is made from either quartz or glass transparent to ultraviolet light.
Description
The present invention relates to a kind of optical waveguide and method for manufacturing optical waveguide, particularly relate to and a kind ofly comprise under-clad layer, the core region that on under-clad layer, forms and cover this under-clad layer and the optical waveguide of the top covering that core region forms and make the method for this optical waveguide.
In field of semiconductor devices, making great efforts to improve travelling speed always and increasing integrated level.Such as, carried out the capacity that a large amount of developments improves the performance of microprocessor and adds large memories.In order further to quicken above-mentioned development, just need be higher along the travelling speed of signal interconnection, the configuration density of signal interconnection is bigger and improve signal delay along electrical wiring, and takes adequate measures to solve owing to improve travelling speed and electromagnetic interference (EMI) that the arranging density of increasing signal interconnection causes also is important.For this reason, studied optical interconnection as the countermeasure that addresses the above problem.Optical interconnection can be considered to use under various conditions, normally is used between the device, between the circuit board in the device or between the chip on the circuit board.Particularly can think and adopt optical waveguide to be fit to transmit such as the signal between chip than short distance as the optical delivery/communication facilities of transmission channel.In order to make the optical delivery/communication facilities that adopts optical waveguide obtain to use widely, importantly to set up the technology of making optical waveguide.
This optical waveguide need have very little light propagation loss and can make by simple manufacturing process.About light propagation loss, can consider the material that adopts light propagation loss little, make optical waveguide as quartz.As proving in the occasion that is applied to optical fiber, quartz has good optical transmission performance, and adopts the quartzy optical waveguide of making to show 0.1dB/cm or following very low transmission loss (TL).Yet adopting the problem of the quartzy optical waveguide of making is that requirement a large amount of manufacturing processes, particularly temperature reach 800 ℃ or higher heat treatment step, and is difficult to guarantee to obtain large-area optical waveguide.Owing to this reason, optical waveguide adopts the macromolecule polymer material that can handle at low temperatures always, makes as polymethylmethacrylate or polyimide.3A～3D is that the optical waveguide that is formed at the relevant technologies on the substrate is described to the core region that is formed by superpolymer below with reference to the accompanying drawings, and wherein each accompanying drawing is the synoptic diagram that the manufacturing process of optical waveguide is shown.
At first, as shown in Figure 3A, on silicon or glass substrate 1, form under-clad layer 2 by spin coating and necessary thermal treatment.On under-clad layer 2, shown in Fig. 3 B, form the big core layer 3 of refractive index ratio under-clad layer 2.
Core layer 3 shown in Fig. 3 C, by photoetching and etching, as reactive ion etching, is carried out graphically to form rectangle core region 3a as the optical waveguide figure.
At last, shown in Fig. 3 D, form top covering 4 by spin coating and necessary thermal treatment and cover core region 3a and under-clad layer 2, thereby obtain buried channel type optical waveguide.
If core region 3a is by dry etching in the operation that is shown in Fig. 3, form as reactive ion etching, then dry etching is normally implemented in oxygen atmosphere.In this dry etching, very big as radio-frequency power, then the surfaceness of each core region 3a becomes big, diminishes as gaseous tension, and then the surfaceness of core region 3a diminishes, but the sidewall of core region 3a usually can be subjected to etching.Therefore, in order to form the core region 3a of the rectangular shape that has little roughness and have pinpoint accuracy, just need depress the execution dry etching at little radio-frequency power and optimum gas.
Yet, if in the above-mentioned dry etching that is used for forming as the core region 3a of optical waveguide, radio-frequency power is set at very little numerical value, though being a few μ m, the thickness of core region 3a can not become very big to manufacturing process's number of the monomode optical waveguide of 10 μ m, but the thickness that core region 3a can occur is the manufacturing process number very big problems of tens μ m to the multimode lightguide of hundreds of μ m, and the sidewall surfaces roughness of each core region 3a and under-clad layer 2 all can become greatly, thereby increases the transmission loss (TL) of light when forming the core region 3a of optical waveguide.
An object of the present invention is to provide and a kind ofly need not the method for optical waveguide that a large amount of manufacturing processes make the core region of the rectangular shape with the little and pin-point accuracy of surfaceness, and provide a kind of light propagation loss very little optical waveguide.
For achieving the above object, a kind of optical waveguide is provided according to a first aspect of the invention, its formation comprises: substrate; The under-clad layer that on substrate, forms; The core region that on under-clad layer, forms; And the top covering that covers under-clad layer and core region formation; Wherein substrate is by making the light material transparent with specific wavelength, and the material that core region can harden during by the light irradiation that is subjected to having specific wavelength.As the above-mentioned light with specific wavelength is ultraviolet light, and then substrate can be by the material to UV transparent, make such as quartz or glass, and the core region material that can harden by being subjected to ultraviolet light irradiation, make such as UV-cured type resin.
A kind of flexible optical waveguide is provided according to a second aspect of the invention, and its formation comprises: under-clad layer; The core region that on under-clad layer, forms; And the top covering that covers under-clad layer and core region formation; Wherein substrate is by making the light material transparent with specific wavelength, and the material that core region can harden during by the light irradiation that is subjected to having specific wavelength.As the above-mentioned light with specific wavelength is ultraviolet light, and then substrate can be by the material to UV transparent, make such as quartz or glass, and the core region material that can harden by being subjected to ultraviolet light irradiation, make such as UV-cured type resin.
A kind of method of making optical waveguide is provided according to a third aspect of the invention we, and it constitutes operation and comprises: form under-clad layer on by the substrate that the light material transparent with specific wavelength is made; On under-clad layer, form the light cut film that makes light ray cut with specific wavelength; Make the graphical figure that has opening that forms of light cut film; On the light cut film, form the core layer of the material of hardening by light irradiation with specific wavelength; Has the light irradiation core layer of specific wavelength so that core layer is positioned at the partially hardened of light cut film opening part from substrate side usefulness; Unhardened part stays the sclerosis part on the removal core layer becomes core region; Remove the light cut film; And form top covering and cover under-clad layer and core region.As above-mentioned light with specific wavelength is ultraviolet light, and then substrate can be made such as quartz or glass by the material to UV transparent; The light cut film can be by metal, as the chromium film production; And the material that core region can harden by being subjected to ultraviolet light irradiation is made such as UV-cured type resin.In addition, in order to form the core region that has little roughness and also have the rectangular shape of pinpoint accuracy, the light with specific wavelength that enters from substrate side is preferably regulated and is become the collimated light beam that has homogeneous energy distribution in irradiation direction.
A kind of method of making flexible optical waveguide is provided according to a forth aspect of the invention, and it constitutes operation and comprises: form diffusion barrier on the substrate transparent to light with specific wavelength; On diffusion barrier, form under-clad layer; On under-clad layer, form the light cut film that makes light ray cut with specific wavelength; Make the graphical figure that has opening that forms of cut film; On the light cut film, form the core layer of the material of hardening by light irradiation with specific wavelength; Has the light irradiation core layer of specific wavelength so that core layer is positioned at the partially hardened of light cut film opening part from substrate side usefulness; Unhardened part stays the sclerosis part on the removal core layer becomes core region; Remove the light cut film; Form top covering and cover under-clad layer and core region; And remove diffusion barrier so that the under-clad layer that on diffusion barrier, forms, core region figure and top covering integral body and substrate separation.As above-mentioned light with specific wavelength is ultraviolet light, and then substrate can be made such as quartz or glass by the material to UV transparent; Diffusion barrier can be by the material that is dissolved in usually in the weak hydrofluorite; The light cut film can be by metal, as the chromium film production; And the material that core region can harden by being subjected to ultraviolet light irradiation is made such as UV-cured type resin.In addition, in order to form the core region that has little roughness and also have the rectangular shape of pinpoint accuracy, the light with specific wavelength that enters from substrate side is preferably regulated and is become the collimated light beam that has homogeneous energy distribution in irradiation direction.
Can form the core region that has little roughness and also have the rectangular shape of the pinpoint accuracy identical according to having the present invention who as above constitutes, thereby can provide the light propagation loss that need not a large amount of manufacturing processes very little optical waveguide at an easy rate with the opening shape of light cut film.
Figure 1A to Fig. 1 G is the synoptic diagram that illustrates according to the manufacturing process of the optical waveguide of the first embodiment of the present invention;
Fig. 2 A to Fig. 2 H is the synoptic diagram that the manufacturing process of flexible optical waveguide according to a second embodiment of the present invention is shown;
Fig. 3 A to Fig. 3 D is the synoptic diagram of manufacturing process that the optical waveguide of prior art is shown.
The present invention can be applicable to its formation and comprises under-clad layer, the core region that on under-clad layer, forms, and, also can be applicable to method for manufacturing optical waveguide for covering the top covering that under-clad layer and core region form.Below, 1A to 1G and Fig. 2 A to 2H describe embodiments of the invention with reference to the accompanying drawings.In these accompanying drawings, adopt same label with the corresponding parts of the parts described in correlation technique.
First embodiment
In this embodiment, the formation of using optical waveguide of the present invention comprises substrate; The under-clad layer that on substrate, forms; The core region that on under-clad layer, forms; And for covering the top covering that under-clad layer and core region form.Below, will method that make a kind of like this optical waveguide be described with reference to the accompanying drawing 1A to 1G of the manufacturing process that optical waveguide schematically is shown.
At first, shown in Figure 1A, on substrate 1, form under-clad layer 2.
Under-clad layer 2 can utilize the common uniform film of thickness formation method, as spin-coating method, spraying process or form the pellicular cascade method in advance and form.In this operation, as what utilize that spin-coating method or spraying process apply on substrate 1 is that the material that can harden by photoirradiation forms under-clad layer 2, and then the material of coating just can utilize photoirradiation to harden like this.Simultaneously, as the material that utilizes spin-coating method or spraying process to apply on substrate 1 is to form under-clad layer 2 by the material that heating is hardened, and then the material of coating just can utilize high temperature to heat to harden like this.
Shown in Figure 1B, forming light cut film 5 on the under-clad layer 2 and carrying out graphical so that will form the position formation open region of core region 3a after on light cut film 5.In other words, the figure that has the light cut film 5 of opening in the position that will form core region 3a is the negative patterning of core region 3a.Light cut film 5 adopts common graphic method graphical, such as adopting photoetching technique on light cut film 5, to form the resist figure and utilizing this resist figure light cut film 5 to be carried out the method for etching as mask, perhaps adopt on under-clad layer 2, to form the resist figure in advance, form light cut film 5 thereon and by peeling off the light cut film 5 patterned methods that make.Light cut film 5 is to make material that the light with specific wavelength 6 of core region 3a sclerosis ends by can be used to make in subsequent handling, and under-clad layer 2 is had good adhesiveness.The object lesson of this material can comprise metal, as chromium and tantalum, and organic material.Make by chromium as light cut film 5, expect that it forms thickness is 10
-8M or above so that be enough to make the light with specific wavelength 6 of core region 3a sclerosis to end, and consider that follow-up light cut film 5 removes operations and expect that more it forms thickness and is approximately 10
-7M.
Afterwards, shown in Fig. 1 C, form core layer 3 and cover light cut film 5 and under-clad layer 2.Core layer 3 can adopt the common method with uniform thickness film that can form to form, such as adopting spin-coating method and spraying process.In addition, the material that core layer 3 can be hardened by light 6 irradiation with specific wavelength, the UV-cured type resin that hardens such as being subjected to ultraviolet light irradiation is made.
Secondly, shown in Fig. 1 D, have the light 6 irradiation core layer 3 of specific wavelength so that be positioned at the zone sclerosis of the figure opening part of light cut film 5 from substrate 1 side utilization.Say in particular, the light 6 with specific wavelength enters and by substrate 1 and under-clad layer 2 from substrate 1 side.Light 6 is subjected to ending of light cut film 5 solid-state parts afterwards, but can be by the opening of light cut film 5.In other words, make that light 6 incides on the core layer 3 that opening part in light cut film 5 forms will make core layer 3 as the part of core region 3a these will have the core region 3a identical thereby form as the partially hardened of core region 3a with the opening shape of light cut film 5.In this occasion, in order to form the core region 3a that has the little sidewall of surfaceness and also have the rectangular shape of the pinpoint accuracy identical with the figure opening shape of light cut film 5, the light 6 that expectation has specific wavelength is to regulate to become the collimated light beam that has homogeneous energy distribution on irradiation direction.
Shown in Fig. 1 E, the part of light 6 with specific wavelength not being exposed on the core layer 3 is removed the core region 3a that has the rectangular shape of the pinpoint accuracy identical with the figure opening shape of light cut film 5 with formation.Utilize organic solvent can be easy to the part of light 6 with specific wavelength not being exposed on the core layer 3 is removed.As core layer 3 is to be made by UV-cured type epoxy resin, can use ethanol to make organic solvent.So rectangular shape that the core region 3a that forms by light 6 irradiation with specific wavelength just has the little sidewall of surfaceness and also has the pinpoint accuracy on the plane vertical with the principal plane of substrate 1.
Shown in Fig. 1 F, remove the light cut film 5 that is retained on the under-clad layer 2.As light cut film 5 are chromium made membranes, can utilize removals such as hydrochloric acid at an easy rate.In this occasion, can not cause damage to core region 3a and under-clad layer 2 when importantly removing light cut film 5.
At last, shown in Fig. 1 G, form and be used for covering the top covering 4 of core region 3a and under-clad layer 2, thereby obtain the accurate and very little optical waveguide of optical transmission loss of its core region 3a figure height.In addition, top covering 4 can utilize common forming to have the method for uniform thickness film, as spin-coating method, spraying process or form the pellicular cascade method in advance and form.In this operation, as what utilize that spin-coating method or spraying process apply on core region 3a and under-clad layer 2 is that the material that can harden by photoirradiation forms top covering 4, and then the material of coating just can utilize photoirradiation to harden like this; And as the material that utilizes spin-coating method or spraying process on core region 3a and under-clad layer 2, applys be to form top covering 4 by the material that heating is hardened, then the material of coating just can utilize high temperature to heat to harden like this.
Second embodiment
In this embodiment, the formation of using flexible optical waveguide of the present invention is included in the under-clad layer that forms on the substrate; The core region that on under-clad layer, forms; And for covering the top covering that under-clad layer and core region form.Below, the accompanying drawing 2A to 2H that reference schematically illustrates the manufacturing process of flexible optical waveguide describes the method for making a kind of like this flexible optical waveguide.
At first, shown in Fig. 2 A, on substrate 1, form diffusion barrier 7, and on diffusion barrier 7, form under-clad layer 2.Similar with first embodiment, substrate 1 is made as glass quartzy or as BK-7 by light 6 material transparent to having specific wavelength.Diffusion barrier 7 also is by light 6 material transparent to having specific wavelength, deielectric-coating as monox or the film making of being made by organic material.In addition, under-clad layer 2 utilizes common forming to have the method for uniform thickness film, as spin-coating method, spraying process or form the pellicular cascade method in advance and form.In this operation, as what utilize that spin-coating method or spraying process apply on diffusion barrier 7 is that the material that can harden by photoirradiation forms under-clad layer 2, and then the material of coating just can utilize photoirradiation to harden like this.Simultaneously, as the material that utilizes spin-coating method or spraying process to apply on diffusion barrier 7 is to form under-clad layer 2 by the material that heating is hardened, and then the material of coating just can utilize high temperature to heat to harden like this.
The subsequent handling of Fig. 2 B to Fig. 2 F is identical with Figure 1B to Fig. 1 F, and therefore identical description is not given unnecessary details.
Afterwards, shown in 2G, form top covering 4 and cover core region 3a and under-clad layer 2.In addition, top covering 4 can adopt the common method with uniform thickness film that can form to form, such as adopting spin-coating method, spraying process or forming the pellicular cascade method in advance.In this operation, as what utilize that spin-coating method or spraying process apply on core region 3a and under-clad layer 2 is that the material that can harden by photoirradiation forms top covering 4, and then the material of coating just can utilize photoirradiation to harden like this; As the material that utilizes spin-coating method or spraying process to apply on core region 3a and under-clad layer 2 is to form top covering 4 by the material that heating is hardened, and then the material of coating just can utilize high temperature to heat to harden like this.
At last, shown in Fig. 2 H, so that separating with substrate 1 to obtain its formation, under-clad layer 2, core region 3a and top covering 4 integral body that form comprise flexible optical waveguide highly precisely graphical and the core region 3a that light propagation loss is very little on diffusion barrier 7 by removing diffusion barrier 7.Can not cause damage to core region 3a, under-clad layer 2 and top covering 4 when in addition, importantly removing diffusion barrier 7.As diffusion barrier 7 is to be made by monox, can utilize parting liquid, removes as weak hydrofluorite.
Though described the preferred embodiments of the present invention with actual conditions, this description only is for the example purpose, can propose various modifications and variations so should be appreciated that the spirit and scope that do not break away from following claims.
Claims (7)
1. optical waveguide, its formation comprises:
Substrate;
The under-clad layer that on described substrate, forms;
The core region that on described under-clad layer, forms; And
Cover the top covering that described under-clad layer and described core region form;
Wherein said substrate is by making the light material transparent with specific wavelength, the material that described core region can harden during by the described light irradiation that is subjected to having specific wavelength.
2. optical waveguide as claimed in claim 1, wherein said substrate can be by the material of hardening by the described light irradiation with specific wavelength.
3. optical waveguide, its formation comprises:
Under-clad layer;
The core region that on described under-clad layer, forms; And
Cover the top covering that described under-clad layer and described core region form;
Wherein said substrate is by making the light material transparent with specific wavelength, and the material that described core region can harden during by the described light irradiation that is subjected to having specific wavelength.
4. method for manufacturing optical waveguide, it constitutes operation and comprises:
On by the substrate that the light material transparent with specific wavelength is made, form under-clad layer;
On described under-clad layer, form the light cut film that makes described light ray cut with specific wavelength;
Make the graphical figure that has opening that forms of described smooth cut film;
On described smooth cut film, form the core layer of the material of hardening by described light irradiation with specific wavelength;
Has the described core layer of described light irradiation of specific wavelength so that described core layer is positioned at the partially hardened of the described opening part of described smooth cut film from described substrate side usefulness;
Removing on the described core layer unhardened part stays described sclerosis part to become core region;
Remove described smooth cut film; And
Form top covering and cover described under-clad layer and described core region.
5. method for manufacturing optical waveguide, it constitutes operation and comprises:
On the substrate transparent, form diffusion barrier to light with specific wavelength;
On described diffusion barrier, form under-clad layer;
On described under-clad layer, form the light cut film that makes described light ray cut with specific wavelength;
Make the graphical figure that has opening that forms of described smooth cut film;
On described smooth cut film, form the core layer of the material of hardening by described light irradiation with specific wavelength;
Has the described core layer of described light irradiation of specific wavelength so that described core layer is positioned at the partially hardened of the described opening part of described smooth cut film from described substrate side usefulness;
Removing on the described core layer unhardened part stays described sclerosis part to become core region;
Remove described smooth cut film;
Form top covering and cover described under-clad layer and described core region; And
Remove described diffusion barrier so that the described under-clad layer that forms, described core region figure and described top covering are whole and described substrate separation on described diffusion barrier.
6. as the method for manufacturing optical waveguide of claim 4 or 5, wherein said substrate is made by quartz or glass, and described core region is made by UV-cured type resin.
7. as the method for manufacturing optical waveguide of claim 4 or 5, wherein said smooth cut film is a metal film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 99110515 CN1243256A (en) | 1998-07-21 | 1999-07-21 | Optical waveguide and mfg. method thereof |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP204945/98 | 1998-07-21 | ||
| CN 99110515 CN1243256A (en) | 1998-07-21 | 1999-07-21 | Optical waveguide and mfg. method thereof |
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| Publication Number | Publication Date |
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| CN1243256A true CN1243256A (en) | 2000-02-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 99110515 Pending CN1243256A (en) | 1998-07-21 | 1999-07-21 | Optical waveguide and mfg. method thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101571610B (en) * | 2008-04-28 | 2013-03-27 | 日立电线株式会社 | Flexible optical waveguide and process for production thereof |
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1999
- 1999-07-21 CN CN 99110515 patent/CN1243256A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101571610B (en) * | 2008-04-28 | 2013-03-27 | 日立电线株式会社 | Flexible optical waveguide and process for production thereof |
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