阅读说明：本技术 一种模斑转换器的制作方法及模斑转换器 (Manufacturing method of spot size converter and spot size converter ) 是由 王亮 蒋凯 蒋忠君 张博健 于 2021-07-16 设计创作，主要内容包括：本公开提供了一种模斑转换器的制作方法及模斑转换器,其中,模斑转换器的制作方法包括：提供一衬底；在上述衬底上生长保护层；在上述保护层上定义楔形结构区域；在上述楔形结构区域,通过一次接触式曝光得到光栅式结构；通过热熔上述光栅式结构,得到楔形结构；通过刻蚀,将上述楔形结构转移至上述衬底上；在上述楔形结构上制作脊波导结构,得到模斑转换器。(The present disclosure provides a method for manufacturing a spot size converter and a spot size converter, wherein the method for manufacturing the spot size converter includes: providing a substrate; growing a protective layer on the substrate; defining a wedge-shaped structure area on the protective layer; obtaining a grating structure in the wedge-shaped structure area through one-time contact exposure; obtaining a wedge-shaped structure by hot melting the grating structure; transferring the wedge-shaped structure to the substrate by etching; and manufacturing a ridge waveguide structure on the wedge-shaped structure to obtain the spot-size converter.)

1. A method of making a spot-size converter, comprising:

providing a substrate;

growing a protective layer on the substrate;

defining a wedge-shaped structure region on the protective layer;

obtaining a grating type structure in the wedge-shaped structure area through one-time contact exposure;

obtaining a wedge-shaped structure by hot melting the grating structure;

transferring the wedge-shaped structure onto the substrate by etching;

and manufacturing a ridge waveguide structure on the wedge-shaped structure to obtain the spot-size converter.

2. The method of claim 1, wherein the protective layer comprises any one of a silicon oxide layer and a silicon nitride layer.

3. The method of claim 1, wherein growing the protective layer on the substrate comprises growing the protective layer on the substrate by plasma enhanced chemical vapor deposition.

4. The method of claim 1, wherein the grating-like structures comprise exposed area and non-exposed area stripe structures arranged at intervals.

5. The method of claim 4, wherein the grating-type structure comprises at least three exposure area stripe structures and two non-exposure area stripe structures, and the widths of the adjacent non-exposure area stripe structures are equal, and the widths of the adjacent exposure area stripe structures are increased or decreased from left to right in sequence.

6. The method of claim 4, wherein the grating-type structure comprises at least three non-exposure area stripe structures and two exposure area stripe structures, and the widths of the stripe structures adjacent to the exposure area are equal, and the widths of the stripe structures adjacent to the non-exposure area increase or decrease from left to right in sequence.

7. The method of claim 6, wherein the exposed area stripe structures comprise a width of 1-4 μm.

8. The method of claim 1, wherein the thickness of the grating-like structure comprises 3-6 μm.

9. The method of claim 1, wherein the transferring the wedge-shaped structures onto the substrate by etching comprises transferring the wedge-shaped structures onto the substrate by an etching process with an etch selectivity ratio of 1-2.

10. A spot-size converter comprising a spot-size converter prepared by the method of any one of claims 1 to 9.

Technical Field

The disclosure relates to the field of photoelectronic technology, and in particular to a method for manufacturing a spot size converter and the spot size converter.

Background

In recent years, with the development of optical communication technology, the integration degree of optoelectronic devices is increasing. In an optical communication system, the size of a spot transmitted by light in a photonic chip is usually in a range from several hundred nanometers to two micrometers, while the size of a spot transmitted by light in an optical fiber is about ten micrometers, and the size of a spot transmitted by light in the optical fiber and the photonic chip has serious size mismatch, so that the mode mismatch of light transmission is further caused, and the transmission efficiency is greatly reduced.

To solve this problem, it is proposed to use a spot-size converter to achieve efficient coupling of the photonic chip to the optical fiber. The spot size converter is generally divided into a horizontal wedge spot size converter and a vertical wedge spot size converter, and the wedge shape in the horizontal direction has attracted a wide attention due to its simple fabrication, but the conversion efficiency is still limited by the vertical direction. The vertical wedge-shaped structure can achieve high conversion efficiency and has great use value, but large-scale production is difficult to realize due to the process difficulty.

For the vertical wedge-shaped spot size converter, the existing manufacturing process mainly comprises the schemes of gray level exposure, dry etching, mask moving, nano imprinting and the like. The gray scale exposure scheme needs to manufacture a gray scale mask, is difficult to design, high in cost and not suitable for a large-size vertical wedge, and cannot be effectively converted into an industrial scheme. The vertical wedge-shaped structure manufactured by dry etching is difficult to ensure the size of the wedge, and industrial production can not be realized. The solution of moving the reticle is relatively simple, but the solution relies on high-end semiconductor equipment to a high degree, and a common contact lithography machine cannot realize the function and needs a large amount of time for each exposure. Although a good wedge-shaped structure can be obtained by nano-imprinting, an additional process flow is added.

Disclosure of Invention

In view of the above problems, the present disclosure provides a method for manufacturing a spot-size converter and a spot-size converter, which are as follows.

One aspect of the present disclosure provides a method for manufacturing a spot-size converter, including: providing a substrate; growing a protective layer on the substrate; defining a wedge-shaped structure area on the protective layer; obtaining a grating structure in the wedge-shaped structure area through one-time contact exposure; obtaining a wedge-shaped structure by hot melting the grating structure; transferring the wedge-shaped structure to the substrate by etching; and manufacturing a ridge waveguide structure on the wedge-shaped structure to obtain the spot-size converter.

According to an embodiment of the present disclosure, the protective layer includes any one of a silicon oxide layer and a silicon nitride layer.

According to an embodiment of the present disclosure, the growing the protective layer on the substrate includes growing the protective layer on the substrate by a plasma enhanced chemical vapor deposition method.

According to the embodiment of the present disclosure, the grating structure includes exposed area bar structures and non-exposed area bar structures arranged at intervals.

According to the embodiment of the present disclosure, wherein the grating structure includes at least three exposure area stripe structures and two non-exposure area stripe structures, and the widths of the adjacent non-exposure area stripe structures are equal, and the widths of the adjacent exposure area stripe structures are sequentially increased or decreased from left to right.

According to the embodiment of the present disclosure, wherein the grating structure comprises at least three non-exposure area bar structures and two exposure area bar structures, the widths of the adjacent non-exposure area bar structures are equal, and the widths of the adjacent non-exposure area bar structures are sequentially increased or decreased from left to right.

According to the embodiment of the present disclosure, the width of the stripe structure of the exposure area comprises 1-4 μm. According to the embodiment of the present disclosure, the thickness of the grating structure includes 3 to 6 μm.

According to the embodiment of the disclosure, the transferring the wedge-shaped structure to the substrate by etching comprises transferring the wedge-shaped structure to the substrate by an etching process with an etching selection ratio of 1-2.

Another aspect of the present disclosure also provides a spot-size converter comprising a spot-size converter prepared by the method of any one of claims 1 to 9.

According to the manufacturing method of the spot size converter, a grating type photoresist structure is obtained through one-time contact exposure, a wedge-shaped structure is obtained through hot melt backflow, the wedge-shaped structure is transferred to a substrate, and a ridge waveguide is manufactured on the wedge-shaped structure, so that the spot size converter is obtained. The method is simple, rapid, low in cost and low in dependence degree on high-end semiconductor equipment, and can meet the high-speed process production target.

Drawings

FIG. 1 schematically illustrates a process flow for fabricating a spot-size converter in an embodiment of the present disclosure;

FIG. 2(a) schematically shows a cross-sectional structure of a substrate;

FIG. 2(b) is a schematic cross-sectional view of a substrate with a protective layer;

FIG. 2(c) is a schematic cross-sectional view of a substrate with a grating structure photoresist;

FIG. 2(d) is a schematic cross-sectional view of a substrate with a wedge-shaped photoresist;

FIG. 2(e) is a schematic cross-sectional view of a substrate with a wedge-shaped structure;

FIG. 2(f) schematically shows a cross-sectional structure of a substrate with a ridge waveguide structure;

FIG. 2(g) schematically illustrates a top view of a substrate with a ridge waveguide structure;

FIG. 3 is a diagram schematically illustrating the characterization result of a wedge-shaped structure in the process of manufacturing a spot-size converter

Fig. 4 schematically shows an overall structural diagram of a spot-size converter manufactured by the present disclosure.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

One aspect of the present disclosure provides a method for manufacturing a spot-size converter, including: providing a substrate; growing a protective layer on the substrate; defining a wedge-shaped structure area on the protective layer; obtaining a grating structure in the wedge-shaped structure area through one-time contact exposure; obtaining a wedge-shaped structure by hot melting the grating structure; transferring the wedge-shaped structure to the substrate by etching; and manufacturing a ridge waveguide structure on the wedge-shaped structure to obtain the spot-size converter.

Fig. 1 schematically shows a manufacturing process of a spot-size converter in an embodiment of the present disclosure.

As shown in fig. 1, the manufacturing process is as follows: providing a substrate; growing a protective layer on the substrate; defining a wedge-shaped structure area on the protective layer; obtaining a grating structure in the wedge-shaped structure area through one-time contact exposure; obtaining a wedge-shaped structure by hot melting the grating structure; transferring the wedge-shaped structure to the substrate by etching; and manufacturing a ridge waveguide structure on the wedge-shaped structure to obtain the spot-size converter.

Fig. 2(a) -2 (f) are schematic structural cross-sectional views obtained at each step in the process of manufacturing the spot-size converter.

And designing a mask plate meeting the requirement according to the size of the wedge-shaped structure, wherein the exposure scale range of the mask plate is 1-4 mu m. According to an embodiment of the present disclosure, the exposure scale of the mask plate may be 1 μm, 2.5 μm, and 4 μm.

Fig. 2(a) schematically shows a cross-sectional structure diagram of a substrate.

As shown in fig. 2(a), the epitaxial substrate 1 includes a ridge waveguide layer 2 and a wedge-shaped structure layer 3. Wherein the epitaxial substrate 1 is composed of multiple layers of materials, only the first layer from top to bottom is shown in fig. 2(a) as a ridge waveguide layer 2 and a second wedge-shaped structure layer 3 from top to bottom, and the rest is not shown.

Fig. 2(b) schematically shows a schematic cross-sectional structure of a substrate with a protective layer.

As shown in fig. 2(b), a protective layer 4 is provided on the substrate.

Fig. 2(c) schematically shows a cross-sectional structure diagram of a substrate with a grating structure photoresist.

In the wedge-shaped structure region, a grating structure 5 is obtained by one contact exposure, as shown in fig. 2 (c).

FIG. 2(d) is a schematic cross-sectional view of a substrate with a wedge-shaped photoresist.

As shown in fig. 2(d), the grating structure on the substrate is thermally fused to obtain a wedge-shaped structure, wherein the characteristic dimension (h) of the wedge-shaped structure₁-h₂) The range of/L is 0.7/1000 to 1.4/1000.

Fig. 2(e) schematically shows a schematic cross-sectional structure of a substrate with a wedge-shaped structure.

The wedge structure is transferred to the substrate by etching, as shown in fig. 2 (e).

Fig. 2(f) schematically shows a schematic cross-sectional structure of a substrate with a ridge waveguide structure.

As shown in fig. 2(f), a ridge waveguide structure is fabricated on the wedge structure of the substrate, resulting in a spot-size converter.

According to the manufacturing method of the spot size converter, a grating type photoresist structure is obtained through one-time contact exposure, a wedge-shaped structure is obtained through hot melt backflow, the wedge-shaped structure is transferred to a substrate, and a ridge waveguide is manufactured on the wedge-shaped structure, so that the spot size converter is obtained. The method is simple, rapid, low in cost and low in dependence degree on high-end semiconductor equipment, and can meet the high-speed process production target.

According to an embodiment of the present disclosure, wherein the protective layer includes any one of a silicon oxide layer and a silicon nitride layer.

According to an embodiment of the present disclosure, wherein growing the protective layer on the substrate includes growing the protective layer on the substrate by plasma enhanced chemical vapor deposition.

According to the embodiment of the present disclosure, the grating structure includes the exposure area stripe structures and the non-exposure area stripe structures arranged at intervals.

According to the embodiment of the present disclosure, the grating structure includes at least three non-exposure area stripe structures and two exposure area stripe structures, and the widths of the adjacent exposure area stripe structures are equal, and the widths of the adjacent non-exposure area stripe structures are sequentially increased or decreased from left to right.

By further limiting the width of the strip-shaped structures of the non-exposure area in the grating structure to be gradually increased or decreased from left to right, the width of the strip-shaped structures of the non-exposure area is unequal, so that a uniform wedge-shaped structure is formed in the hot melting process.

According to the embodiment of the present disclosure, the width of the stripe structure of the exposure area comprises 1-4 μm. According to an embodiment of the present disclosure, the width of the exposure area stripe structures may be, for example, 1 μm, 2.5 μm, or 4 μm.

According to the embodiment of the present disclosure, wherein, the grating structure includes at least three exposure area bar structures and two non-exposure area bar structures, and the width of the adjacent non-exposure area bar structures is equal, and the width of the above exposure area bar structures is increased or decreased from left to right in turn.

The width of the strip-shaped structures of the exposure area in the grating structure is further limited to be gradually increased or decreased from left to right, so that the width of the strip-shaped structures of the exposure area is unequal, and uniform wedge-shaped structures are formed in the hot melting process.

According to the embodiment of the disclosure, the thickness of the grating structure comprises 3-6 μm. According to embodiments of the present disclosure, the thickness of the grating structure may be, for example, 3 μm, 4 μm, 5 μm, or 6 μm.

According to the embodiment of the disclosure, the transferring of the wedge-shaped structure to the substrate through etching comprises transferring the wedge-shaped structure to the substrate through an etching process with an etching selection ratio of 1-2. According to embodiments of the present disclosure, wherein the etch selectivity may be 1, 1.5, or 2.

In the embodiment of the disclosure, the etching selection ratio is defined, so that the wedge-shaped structure can be stably transferred to the substrate according to the size requirement through etching.

Fig. 2(g) schematically shows a top view of a substrate with a ridge waveguide structure.

As shown in FIG. 2(g), according to the embodiment of the disclosure, the characteristic dimension W1 of the ridge waveguide on the spot size converter manufactured by the disclosure is 1.7-2.5 μm, the depth is 170-250 nm, and the characteristic dimension W2 of the spot size converter is 12-16 μm.

FIG. 3 is a diagram schematically illustrating the characterization result of the wedge-shaped structure during the fabrication of the spot-size converter.

As shown in FIG. 3, the resulting feature size (h) of the wedge measured in the figure₁-h₂) the/L range is 0.8/800, and the characteristic dimension range is 0.7/1000-1.4/1000 by adjusting the ratio of the width of the exposure area to the width of the non-exposure area or the thickness of the photoresist.

Fig. 4 schematically shows an overall structural diagram of a spot-size converter manufactured by the present disclosure.

As shown in fig. 4, another aspect of the present disclosure also provides a spot-size converter, which is manufactured by the above method. The spot size converter includes a substrate with a wedge-shaped structure, and a ridge waveguide structure on the upper surface of the substrate.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.