阅读说明：本技术 一种光膜转换器及其制备方法 (Light film converter and preparation method thereof ) 是由 王奕琼 魏星 冯大增 梁虹 武爱民 于 2020-01-19 设计创作，主要内容包括：本申请涉及一种光膜转换器及其制备方法,该光膜转换器集成在硅波导上,并与光纤连接。光膜转换器包括衬底层、电介质层、第一波导层和第二波导层；第一波导层包括第一波导和第一电介质槽；第一波导的顶部和第二波导层接触,第一波导的底部和电介质层接触；第一波导的宽度由远离光纤至靠近光纤的一端逐渐增大；第一电介质槽围绕设置于第一波导的外侧；第一电介质槽的底部与电介质层连通；第二波导层包括第二波导；第二波导朝向光纤的端面与第一波导朝向光纤的端面互相配合,用于耦合光纤。本申请通过上述光膜转换器实现光膜尺度从硅波导到光纤的尺度转换,如此,可以降低芯片与光纤光耦合损耗,可以降低光纤成本。(The present application relates to an optical film converter integrated on a silicon waveguide and connected to an optical fiber and a method of making the same. The optical film converter comprises a substrate layer, a dielectric layer, a first waveguide layer and a second waveguide layer; the first waveguide layer comprises a first waveguide and a first dielectric groove; the top of the first waveguide is in contact with the second waveguide layer, and the bottom of the first waveguide is in contact with the dielectric layer; the width of the first waveguide is gradually increased from the end far away from the optical fiber to the end close to the optical fiber; the first dielectric groove is arranged around the outer side of the first waveguide; the bottom of the first dielectric groove is communicated with the dielectric layer; the second waveguide layer comprises a second waveguide; the end face of the second waveguide facing the optical fiber is mutually matched with the end face of the first waveguide facing the optical fiber for coupling the optical fiber. This application realizes the yardstick conversion of light membrane yardstick from silicon waveguide to optic fibre through above-mentioned light membrane converter, so, can reduce chip and optic fibre optical coupling loss, can reduce the optic fibre cost.)

1. An optical film converter, wherein said optical film converter is integrated on a silicon waveguide, said optical film converter being connected to an optical fiber; the light film converter comprises a substrate layer (100), a dielectric layer (200), a first waveguide layer (300), and a second waveguide layer (400);

the first waveguide layer (300) comprises a first waveguide (301) and a first dielectric trench (302);

the top of the first waveguide (301) is in contact with the second waveguide layer (400), and the bottom of the first waveguide (301) is in contact with the dielectric layer (200); the width of the first waveguide (301) is gradually increased from the far end to the end close to the optical fiber; the first dielectric groove (302) is arranged around the outer side of the first waveguide (301); the bottom of the first dielectric trench (302) is in communication with the dielectric layer (200);

the second waveguide layer (400) comprises a second waveguide (401); the end face of the second waveguide (401) facing the optical fiber is mutually mated with the end face of the first waveguide (301) facing the optical fiber for coupling the optical fiber.

2. The light film converter according to claim 1, wherein the end face of the first waveguide layer (300) adjacent to the second waveguide layer (400) is etched with a second dielectric trench (303);

the second dielectric trench (303) communicates with the first dielectric trench (302).

3. The light film converter according to claim 1, wherein the first waveguide (301) is trapezoidal in cross-section;

the first dielectric trench (302) is V-shaped.

4. The light film converter according to claim 1, wherein the width of the first waveguide (301) towards the end face of the optical fiber ranges from 6.0 microns to 15.0 microns;

the width of the second waveguide (401) towards the end face of the optical fiber ranges from 6.0 microns to 15.0 microns;

the optical fiber has a diameter in the range of 6.0 microns to 15.0 microns.

5. The light film converter according to claim 1,

the second waveguide (401) has a height in the range of 0.1 to 5.0 microns;

the sum of the height of the first waveguide (301) and the height of the second waveguide (401) ranges from 6.0 microns to 15.0 microns.

6. The light film converter according to claim 1, wherein the width of the end face of the first waveguide (301) facing away from the optical fiber ranges from 0.01 microns to 1.5 microns;

the width of the second waveguide (401) at the end face facing away from the optical fiber ranges from 0.2 to 4.0 microns.

7. The light film converter according to claim 2, wherein the first dielectric groove (302) has a width in the range of 0.1 to 3.0 microns;

the second dielectric trench (303) has a depth in a range of 0.1 to 3.0 microns.

8. The light film converter according to claim 1, wherein the dielectric material of the dielectric layer (200) comprises at least one of silicon oxide and silicon nitride.

9. A method of making a light film converter, comprising:

depositing an insulating layer, a dielectric layer and a first silicon layer in sequence;

photoetching and silicon dry method are carried out on the first silicon layer, and a deep groove is etched to the dielectric layer;

photoetching and silicon dry method are carried out on the surface of the first silicon layer, and a groove with a preset depth is etched;

filling the deep groove and the groove with dielectric medium to form a first dielectric medium groove and a second dielectric medium groove;

implanting hydrogen ions into the second silicon layer to form an implanted layer; wherein the implantation energy is less than or equal to 120 kilo-electron volts, and the implantation dosage is 5E 6-7E 6 per square centimeter;

performing surface activation treatment on the implanted second silicon layer;

bonding the first silicon layer and the second silicon layer;

performing heat treatment on the bonded first silicon layer and the bonded second silicon layer; wherein the treatment temperature is less than or equal to 700 ℃, and the treatment atmosphere is argon or nitrogen;

stripping the second silicon layer from the injection layer to obtain the light film converter;

cleaning, reinforcing and polishing the light film converter; wherein the reinforcement temperature is less than or equal to 1250 ℃, and the reinforcement treatment time is less than 6 hours.

10. The method according to claim 9, wherein after the implanting the second silicon layer using hydrogen ions to form the implanted layer and before the subjecting the implanted second silicon layer to the surface activation treatment, the method further comprises:

and removing the oxide layer on the surface of the implanted second silicon layer by using hydrofluoric acid.

11. The method of claim 9, wherein the subjecting the implanted second silicon layer to a surface activation process comprises:

performing surface activation treatment on the implanted second silicon layer by using low-temperature plasma; wherein the low temperature plasma includes any one of oxygen plasma, nitrogen plasma, and argon plasma;

or; performing surface activation treatment on the injected second silicon layer by using ammonia water;

or; and contacting the surface of the implanted second silicon layer by using a soft brush to perform surface activation treatment.

12. The method of making according to claim 9, wherein said cleaning, reinforcing and polishing said light film converter comprises:

after cleaning and reinforcing the light film converter, removing an oxide layer on the surface of the light film converter by using hydrofluoric acid;

the light film converter surface is made flat and smooth by chemical mechanical polishing.

Technical Field

The application relates to the technical field of semiconductors, in particular to an optical film converter and a preparation method thereof.

Background

With the increasing requirements of people on information transmission and processing speed and the coming of the multi-core computing era, electrical interconnection based on metal becomes a development bottleneck due to defects of overheating, delay, electronic interference and the like. And the problem can be effectively solved by adopting optical interconnection to replace electrical interconnection. Silicon-based optical interconnects are preferred for their incomparable cost and technical advantages in the implementation of optical interconnects. The silicon-based optical interconnection can not only play the advantages of high optical interconnection speed, large bandwidth, interference resistance, low power consumption and the like, but also fully utilize the advantages of mature microelectronic process, high-density integration, high yield, low cost and the like, and the development of a new generation of high-performance computer and data communication system is certainly promoted, so that the silicon-based optical interconnection has wide market application prospect.

The core technology of silicon-based optical interconnection is to realize devices with various photoelectric functions on silicon, such as a photoelectric detector, a modulator, a wavelength division multiplexer and the like. The optical loss of the integrated optoelectronic device module is an important technical index, and the chip-to-fiber coupling loss is also an important parameter. In order to reduce the optical coupling loss caused by the size mismatch between the silicon optoelectronic integrated chip and the standard optical fiber, the lensed optical fiber, the small-core optical fiber and the core-shrinking optical fiber are often used as transition optical film switching optical fibers. As shown in fig. 1(a), it shows the prior art solution to shrink the optical film to the dimension of the silicon waveguide by switching the optical film of the standard optical fiber to the core-shrinking optical fiber; as shown in fig. 1(b), a schematic diagram of a cross section a-a' of a silicon-based optical waveguide based on soi (silicon on insulator) is shown; as shown in FIG. 1(c), a comparison of the B-B' dimension of the coupling end face of the silicon waveguide and the optical film of the core-reduced optical fiber is shown. The prior art has the defects that the coupling insertion loss of the core-shrinking optical fiber and the waveguide of the integrated photoelectric chip has poor coupling alignment precision tolerance, and the core-shrinking optical fiber has higher cost than a standard optical fiber.

Disclosure of Invention

The embodiment of the application provides an optical film converter and a preparation method thereof, which can reduce the optical coupling loss of a chip and an optical fiber and can reduce the cost of the optical fiber.

In one aspect, embodiments of the present application provide an optical film converter integrated on a silicon waveguide, the optical film converter being connected to an optical fiber; the optical film converter comprises substrate layer 100, dielectric layer 200, first waveguide layer 300, and second waveguide layer 400;

the first waveguide layer 300 includes a first waveguide 301 and a first dielectric trench 302;

the top of the first waveguide 301 is in contact with the second waveguide layer 400 and the bottom of the first waveguide 301 is in contact with the dielectric layer 200; the width of the first waveguide 301 gradually increases from the end far away from the optical fiber to the end near the optical fiber; a first dielectric groove 302 is disposed around the outside of the first waveguide 301; the bottom of the first dielectric trench 302 communicates with the dielectric layer 200;

the second waveguide layer 400 includes a second waveguide 401; the end face of the second waveguide 401 facing the optical fiber is mated with the end face of the first waveguide 301 facing the optical fiber for coupling the optical fiber.

In another aspect, an embodiment of the present application provides a method for manufacturing a light film converter, including:

depositing an insulating layer, a dielectric layer and a first silicon layer in sequence;

photoetching and silicon dry method are carried out on the first silicon layer, and a deep groove is etched to the dielectric layer;

photoetching and silicon dry method are carried out on the surface of the first silicon layer, and a groove with a preset depth is etched;

filling the deep groove and the groove with dielectric medium to form a first dielectric medium groove and a second dielectric medium groove;

implanting hydrogen ions into the second silicon layer to form an implanted layer; wherein the implantation energy is less than or equal to 120 kilo-electron volts, and the implantation dosage is 5E 6-7E 6 per square centimeter;

performing surface activation treatment on the implanted second silicon layer;

bonding the first silicon layer and the second silicon layer;

performing heat treatment on the bonded first silicon layer and the bonded second silicon layer; wherein the treatment temperature is less than or equal to 700 ℃, and the treatment atmosphere is argon or nitrogen;

stripping the second silicon layer from the injection layer to obtain the light film converter;

cleaning, reinforcing and polishing the light film converter; wherein the reinforcement temperature is less than or equal to 1250 ℃, and the reinforcement treatment time is less than 6 hours.

The light film converter and the preparation method thereof provided by the embodiment of the application have the following beneficial effects:

the optical film converter is integrated on the silicon waveguide and connected with the optical fiber; the optical film converter comprises substrate layer 100, dielectric layer 200, first waveguide layer 300, and second waveguide layer 400; the first waveguide layer 300 includes a first waveguide 301 and a first dielectric trench 302; the top of the first waveguide 301 is in contact with the second waveguide layer 400 and the bottom of the first waveguide 301 is in contact with the dielectric layer 200; the width of the first waveguide 301 gradually increases from the end far away from the optical fiber to the end near the optical fiber; a first dielectric groove 302 is disposed around the outside of the first waveguide 301; the bottom of the first dielectric trench 302 communicates with the dielectric layer 200; the second waveguide layer 400 includes a second waveguide 401; the end face of the second waveguide 401 facing the optical fiber is mated with the end face of the first waveguide 301 facing the optical fiber for coupling the optical fiber. This application realizes the yardstick conversion of light membrane yardstick from silicon waveguide to optic fibre through above-mentioned light membrane converter, so, can reduce chip and optic fibre optical coupling loss, can reduce the optic fibre cost.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art optical film transition of a silicon waveguide and an optical fiber according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a light film converter according to an embodiment of the present application;

FIG. 3 is a top view of a light film converter according to an embodiment of the present application;

FIG. 4 is a schematic diagram of an optical film converter and an optical fiber coupling end according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of the first waveguide layer in a top view according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a section C-C' in FIG. 3 according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a section D-D' in FIG. 3 according to an embodiment of the present disclosure;

FIG. 8 is a schematic structural diagram of a section E-E' in FIG. 3 according to an embodiment of the present disclosure;

fig. 9 is a schematic view of a manufacturing process of a light film converter according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or server that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 2, fig. 2 is a schematic structural diagram of an optical film converter integrated on a silicon waveguide and connected to an optical fiber according to an embodiment of the present disclosure; the optical film converter comprises substrate layer 100, dielectric layer 200, first waveguide layer 300, and second waveguide layer 400;

the first waveguide layer 300 includes a first waveguide 301 and a first dielectric trench 302;

the top of the first waveguide 301 is in contact with the second waveguide layer 400 and the bottom of the first waveguide 301 is in contact with the dielectric layer 200; the width of the first waveguide 301 gradually increases from the end far away from the optical fiber to the end near the optical fiber; a first dielectric groove 302 is disposed around the outside of the first waveguide 301; the bottom of the first dielectric trench 302 communicates with the dielectric layer 200;

the second waveguide layer 400 includes a second waveguide 401; the end face of the second waveguide 401 facing the optical fiber is mated with the end face of the first waveguide 301 facing the optical fiber for coupling the optical fiber.

According to the embodiment of the application, the optical film converter is integrated in the chip, so that the scale conversion of the optical film scale from the silicon waveguide to the standard optical fiber can be realized, and the optical film converter has the advantages that the influence of the coupling alignment tolerance of the silicon photoelectric integrated chip and the optical fiber on the coupling insertion loss can be greatly reduced, so that the optical insertion loss of a device is greatly reduced; and the standard optical fiber can be used for replacing a lensed optical fiber, a small-core optical fiber or a core-shrinking optical fiber, so that the cost of the optical fiber is greatly reduced.

In the embodiment of the present application, as shown in fig. 2, the end surface of first waveguide layer 300 near second waveguide layer 400 is etched with second dielectric trench 303.

Optionally, the second dielectric trench 303 communicates with the first dielectric trench 302.

Optionally, the dielectric material of the dielectric layer 200 includes at least one of silicon oxide and silicon nitride.

Referring to fig. 3, fig. 3 is a top view of a light film converter according to an embodiment of the present application, wherein a portion of the second waveguide layer 400 above the light film converter is removed for ease of understanding and illustration. The optical film converter is integrated at one end of the silicon waveguide, and the other end of the optical film converter is used for coupling with an optical fiber, please refer to fig. 4, and fig. 4 is a schematic structural diagram of a coupling end face of the optical film converter and the optical fiber according to an embodiment of the present application.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a first waveguide layer in a top view according to an embodiment of the present disclosure. Alternatively, referring to fig. 2, 4 and 5, the first waveguide 301 has a trapezoidal cross section, and the first dielectric groove 302 has a V-shape with a certain width at the bottom. It should be noted that the cross-sectional edge of the first waveguide 301 may be linear or non-linear.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a cross section C-C 'of fig. 3 according to an embodiment of the present application, where the cross section C-C' is a coupling end surface of the optical film converter and the optical fiber. The width W1 of the end face of the first waveguide 301 facing the optical fiber ranges from 6.0 micrometers to 15.0 micrometers; the width W2 of the end face of the second waveguide 401 facing the optical fiber ranges from 6.0 micrometers to 15.0 micrometers; the sum H1 of the height of the first waveguide 301 and the height of the second waveguide 401 ranges from 6.0 microns to 15.0 microns.

Optionally, the standard optical fiber has a diameter in the range of 6.0 microns to 15.0 microns.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a section D-D' in fig. 3 according to an embodiment of the present disclosure, in which a width W3 of an end surface of the first waveguide 301 facing away from the optical fiber ranges from 0.5 micrometers to 1.5 micrometers; the width W4 of the first dielectric trench 302 ranges from 0.1 microns to 3.0 microns; the depth H2 of the second dielectric trench 303 ranges from 0.1 micron to 3.0 microns.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a section E-E 'of fig. 3 according to an embodiment of the present application, where the section E-E' is an integrated end surface of a light film converter and a silicon waveguide. The width W5 of the end face of the second waveguide 401 facing away from the optical fiber ranges from 0.2 microns to 4.0 microns; the height H3 of the second waveguide 401 ranges from 0.1 microns to 5.0 microns.

An embodiment of the present application further provides a method for manufacturing a light film converter, please refer to fig. 9, and fig. 9 is a schematic diagram of a manufacturing process of the light film converter provided in the embodiment of the present application. As shown in fig. 9(a), comprising sequentially depositing an insulating layer 100, a dielectric layer 200 and a first silicon layer 300; as shown in fig. 9(b), the first silicon layer 300 is subjected to photolithography and silicon dry process to etch a deep trench to the dielectric layer 200; as shown in fig. 9(c), the surface of the first silicon layer 300 is subjected to photolithography and silicon dry etching, and a groove with a preset depth of y is etched; as shown in fig. 9(d), the first dielectric trench 302 and the second dielectric trench 303 are formed by dielectric filling of the deep trench and the trench; as shown in fig. 9(e), the second silicon layer 400 is implanted with hydrogen ions to form an implanted layer; wherein the implantation energy is less than or equal to 120 kilo-electron volts, and the implantation dosage is 5E 6-7E 6 per square centimeter; performing surface activation treatment on the implanted second silicon layer 400; as shown in fig. 9(f), the first silicon layer 300 and the second silicon layer 400 are bonded; performing heat treatment on the bonded first silicon layer 300 and second silicon layer 400; wherein the treatment temperature is less than or equal to 700 ℃, and the treatment atmosphere is argon or nitrogen; as shown in fig. 9(g), the second silicon layer 400 was peeled off from the implanted layer to obtain a light film converter; cleaning, reinforcing and polishing the light film converter; wherein the reinforcement temperature is less than or equal to 1250 ℃, and the reinforcement treatment time is less than 6 hours.

Alternatively, as shown in fig. 9(h), a thicker optical film converter can be obtained by silicon epitaxy (epitaxiy) on the second silicon layer 400.

Optionally, implanting hydrogen ions into the second silicon layer 400, after forming the implanted layer, and before performing surface activation on the implanted second silicon layer 400, the method further includes: the oxide layer on the surface of the implanted second silicon layer 400 is removed using hydrofluoric acid.

In an alternative embodiment of performing the surface activation treatment on the implanted second silicon layer 400, the surface activation treatment is performed on the implanted second silicon layer 400 using low-temperature plasma; wherein the low temperature plasma includes any one of oxygen plasma, nitrogen plasma, and argon plasma.

In another alternative embodiment of performing the surface activation treatment on the implanted second silicon layer 400, the implanted second silicon layer 400 is subjected to the surface activation treatment using ammonia water.

In another alternative embodiment of performing the surface activation treatment on the implanted second silicon layer 400, the surface activation treatment is performed by contacting the surface of the implanted second silicon layer 400 with a soft brush.

An alternative embodiment for cleaning, reinforcing, and polishing a light film converter, comprising: after cleaning and reinforcing the optical film converter, removing an oxide layer on the surface of the optical film converter by using hydrofluoric acid; the surface of the light film converter was made flat and smooth by Chemical Mechanical Polishing (CMP).

In view of the above embodiments of an optical film converter and method of making the same provided herein, an optical film converter is integrated on a silicon waveguide and connected to an optical fiber; the optical film converter comprises substrate layer 100, dielectric layer 200, first waveguide layer 300, and second waveguide layer 400; the first waveguide layer 300 includes a first waveguide 301 and a first dielectric trench 302; the top of the first waveguide 301 is in contact with the second waveguide layer 400 and the bottom of the first waveguide 301 is in contact with the dielectric layer 200; the width of the first waveguide 301 gradually increases from the end far away from the optical fiber to the end near the optical fiber; a first dielectric groove 302 is disposed around the outside of the first waveguide 301; the bottom of the first dielectric trench 302 communicates with the dielectric layer 200; the second waveguide layer 400 includes a second waveguide 401; the end face of the second waveguide 401 facing the optical fiber is mated with the end face of the first waveguide 301 facing the optical fiber for coupling the optical fiber. This application realizes the yardstick conversion of light membrane yardstick from silicon waveguide to optic fibre through above-mentioned light membrane converter, so, can reduce chip and optic fibre optical coupling loss, can reduce the optic fibre cost.

It is noted that the present specification provides the method steps as in the examples, but that more or fewer steps may be included based on routine or non-inventive labor. The order of steps recited in the embodiments is merely one manner of performing the steps in a multitude of orders and does not represent the only order of execution.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.