Filter manufacturing method and filter

Abstract

The invention discloses a filter manufacturing method and a filter, and relates to the technical field of filters, and the filter manufacturing method comprises the following steps: preparing a substrate; forming a buried layer on the substrate; forming an insulating layer on the buried layer; forming a multi-layer thin film structure on the insulating layer; forming each layer of thin film structure comprises forming a lower dielectric layer thin film, an upper dielectric layer thin film and a semiconductor layer thin film located between the lower dielectric layer thin film and the upper dielectric layer thin film; photoetching and etching the semiconductor layer film to form a plurality of ridge-shaped waveguide structures; and each semiconductor layer film surrounds the ridge waveguide structure of the layer. The multi-layer film structure is designed and comprises the lower dielectric layer, the upper dielectric layer and the semiconductor layer, the propagation path and phase delay of light waves can be accurately controlled, the multi-layer film structure can achieve selective transmission of light with specific wavelength by accurately controlling the thickness of each layer of film and the refractive index of the material, and the light transmission efficiency is improved. The method is crucial to applications requiring accurate wavelength control, such as optical communication and spectral analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and in particular to a method for manufacturing a filter and the filter. Background Art

[0002] Filters can effectively filter out a certain frequency point or a certain frequency range to obtain a signal with the required frequency, and have important applications in the field of modern electronic technology.

[0003] In optical communications, spectrum analysis, and laser technology, it is necessary to be able to accurately select light of a specific wavelength to achieve efficient signal transmission and precise wavelength control. Traditional filters may not provide sufficient wavelength selectivity, or it may be difficult to achieve a balance between wavelength selectivity, bandwidth, and insertion loss. Summary of the invention

[0004] In view of the existing problems in the manufacture of filters and filters, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is that the traditional filter has great limitations.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for manufacturing a filter, which comprises the following steps:

[0008] preparing a substrate;

[0009] forming a buried layer on the substrate;

[0010] forming an insulating layer on the buried layer;

[0011] forming a multi-layer thin film structure on the insulating layer;

[0012] Wherein, forming each layer of the thin film structure includes forming a lower dielectric layer thin film, an upper dielectric layer thin film, and a semiconductor layer thin film located between the lower dielectric layer thin film and the upper dielectric layer thin film;

[0013] The semiconductor layer film is photolithographically and etched to form a plurality of ridge waveguide structures; wherein each layer of the semiconductor layer film surrounds the ridge waveguide structure of the layer.

[0014] As a preferred solution of the method for manufacturing the filter of the present invention, wherein: the multi-layer thin film structure includes a third thin film layer;

[0015] By etching the semiconductor layer film in the third film layer, a ridge waveguide structure is formed as an output tapered waveguide and an input tapered waveguide on the substrate.

[0016] As a preferred solution of the method for manufacturing the filter of the present invention, the buried layer includes at least one of a silicon dioxide layer, a phosphosilicate glass layer, and a silicon carbide layer.

[0017] As a preferred solution of the method for manufacturing the filter of the present invention, the insulating layer includes a silicon dioxide layer.

[0018] As a preferred solution of the method for manufacturing the filter of the present invention, the material of the semiconductor layer thin film includes at least one of silicon nitride, amorphous silicon, gallium arsenide, indium phosphide, and nanocrystal;

[0019] Wherein, when the material of the semiconductor layer thin film includes silicon nitride, the preparation method further includes: forming a coating layer on the surface of the thin film structure;

[0020] Specifically:

[0021] The substrate formed with the thin film structure is placed in a chamber filled with oxygen plasma, so that the oxygen plasma oxidizes the thin film structure to form the coating layer.

[0022] As a preferred solution of the method for manufacturing the filter of the present invention, wherein: the material of the lower dielectric layer thin film is silicon dioxide;

[0023] The material of the upper dielectric layer thin film is at least one of a silicon dioxide layer and a silicon nitride layer;

[0024] The thickness of the lower dielectric layer film and the upper dielectric layer film is 800nm-1200nm.

[0025] As a preferred solution of the method for manufacturing the filter of the present invention, wherein: the substrate is at least one of a semiconductor substrate and a first dielectric layer;

[0026] Wherein, when the substrate is a semiconductor base, the material of the semiconductor base includes at least one of silicon, gallium arsenide, gallium nitride, doped silicon, and doped silicon carbide;

[0027] When the substrate is a semiconductor base and a first dielectric layer, the material of the semiconductor base includes silicon, gallium arsenide, gallium nitride, and aluminum nitride; and the material of the first dielectric layer is silicon dioxide.

[0028] As a preferred solution of the method for manufacturing the filter of the present invention, wherein: the multi-layer thin film structure includes N layers of thin film structure, wherein N is a positive integer, and N≥2;

[0029] The method for preparing the multilayer thin film structure also includes: before forming the i-th thin film structure, forming a covering layer covering the i-1th thin film structure on the i-1th thin film structure, and the covering layer is a silicon dioxide layer to isolate the i-th thin film structure from the i-1th thin film structure, so that the i-th thin film structure and the i-1th thin film structure are independent of each other.

[0030] As a preferred solution of the filter manufacturing method of the present invention, the steps of photolithography and etching the semiconductor layer thin film include:

[0031] forming a first mask layer on the semiconductor layer film, wherein the first mask layer includes a plurality of grooves;

[0032] forming the upper dielectric layer thin film on the first mask layer;

[0033] forming a second mask layer on the upper dielectric film;

[0034] Etching the second mask layer to form a plurality of openings;

[0035] Using the etched second mask layer as a mask, etching the upper dielectric layer film and the semiconductor layer film to form the ridge waveguide structure;

[0036] The second mask layer is removed, and a third mask layer is formed on the surface of the upper dielectric layer film and the ridge waveguide structure after the second mask layer is removed, wherein the third mask layer includes a plurality of grooves;

[0037] Using the first mask layer and the third mask layer as masks, etching the upper dielectric layer film and the semiconductor layer film to form the lower dielectric layer film;

[0038] The first mask layer and the third mask layer are removed.

[0039] In a second aspect, the present invention provides a filter, which is manufactured using the filter manufacturing method as described above.

[0040] The beneficial effects of the present invention are:

[0041] By designing a multilayer thin film structure, including a lower dielectric layer, an upper dielectric layer, and a semiconductor layer, the propagation path and phase delay of light waves can be precisely controlled, thereby achieving selective transmission of specific wavelengths. Secondly, the multilayer thin film structure can achieve selective transmission of light of specific wavelengths by precisely controlling the thickness of each layer of the film and the refractive index of the material, which is crucial for applications that require precise wavelength control, such as optical communications and spectral analysis. Finally, due to the settings of ridge waveguides and tapered waveguides, the propagation path and mode of light can be further precisely controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0043] Figure 1 Flow chart of the method for making the filter. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0045] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0046] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0047] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0048] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] Example 1

[0051] Reference Figure 1 , which is the first embodiment of the present invention, provides a method for manufacturing a filter, comprising the following steps:

[0052] S1. Prepare a substrate.

[0053] The substrate is a semiconductor base;

[0054] The material of the semiconductor substrate includes silicon.

[0055] S2. Forming a buried layer on the substrate.

[0056] The buried layer includes a silicon dioxide layer, a phosphosilicate glass layer and a silicon carbide layer.

[0057] S3. Forming an insulating layer on the buried layer.

[0058] The insulating layer includes a silicon dioxide layer.

[0059] S4. Forming a multi-layer thin film structure on the insulating layer.

[0060] The multi-layer film structure includes a third film layer;

[0061] By etching the semiconductor layer film in the third film layer, a ridge waveguide structure is formed as an output tapered waveguide and an input tapered waveguide on the substrate.

[0062] The multi-layer film structure comprises a 5-layer film structure;

[0063] The method for preparing the multilayer thin film structure also includes: before forming the fifth thin film structure, forming a covering layer covering the fourth thin film structure on the fourth thin film structure, and the covering layer is a silicon dioxide layer to isolate the fifth thin film structure from the fourth thin film structure, so that the fifth thin film structure and the fourth thin film structure are independent of each other.

[0064] Wherein, forming each layer of the thin film structure includes forming a lower dielectric layer thin film, an upper dielectric layer thin film, and a semiconductor layer thin film located between the lower dielectric layer thin film and the upper dielectric layer thin film;

[0065] The material of the lower dielectric layer film is silicon dioxide;

[0066] The material of the upper dielectric layer film is a silicon dioxide layer;

[0067] The thickness of the lower dielectric layer film and the upper dielectric layer film is 800 nm.

[0068] The semiconductor layer film is photolithographically and etched to form a plurality of ridge waveguide structures; wherein each layer of the semiconductor layer film surrounds the ridge waveguide structure of the layer.

[0069] Materials for semiconductor layer films include amorphous silicon, gallium arsenide, indium phosphide and nanocrystals.

[0070] The steps of photolithography and etching the semiconductor layer film include:

[0071] forming a first mask layer on the semiconductor layer film, wherein the first mask layer includes a plurality of grooves;

[0072] forming the upper dielectric layer thin film on the first mask layer;

[0073] forming a second mask layer on the upper dielectric film;

[0074] Etching the second mask layer to form a plurality of openings;

[0075] Using the etched second mask layer as a mask, etching the upper dielectric layer film and the semiconductor layer film to form the ridge waveguide structure;

[0076] The second mask layer is removed, and a third mask layer is formed on the surface of the upper dielectric layer film and the ridge waveguide structure after the second mask layer is removed, wherein the third mask layer includes a plurality of grooves;

[0077] Using the first mask layer and the third mask layer as masks, etching the upper dielectric layer film and the semiconductor layer film to form the lower dielectric layer film;

[0078] The first mask layer and the third mask layer are removed.

[0079] Example 2

[0080] Reference Figure 1 , which is a second embodiment of the present invention, and this embodiment still provides a method for manufacturing a filter, comprising the following steps:

[0081] S1. Prepare a substrate.

[0082] The substrate is a semiconductor base and a first dielectric layer;

[0083] Wherein, the material of the semiconductor substrate includes silicon, gallium arsenide, gallium nitride, and aluminum nitride;

[0084] The material of the first dielectric layer is silicon dioxide.

[0085] S2. Forming a buried layer on the substrate.

[0086] The buried layer includes a silicon dioxide layer.

[0087] S3. Form an insulating layer on the buried layer.

[0088] The insulating layer includes a silicon dioxide layer.

[0089] S4. Forming a multi-layer thin film structure on the insulating layer.

[0090] The multi-layer film structure includes a third film layer;

[0091] By etching the semiconductor layer film in the third film layer, a ridge waveguide structure is formed as an output tapered waveguide and an input tapered waveguide on the substrate.

[0092] The multi-layer film structure comprises a 5-layer film structure;

[0093] The method for preparing the multilayer thin film structure also includes: before forming the fifth thin film structure, forming a covering layer covering the fourth thin film structure on the fourth thin film structure, and the covering layer is a silicon dioxide layer to isolate the fifth thin film structure from the fourth thin film structure, so that the fifth thin film structure and the fourth thin film structure are independent of each other.

[0094] Wherein, forming each layer of the thin film structure includes forming a lower dielectric layer thin film, an upper dielectric layer thin film, and a semiconductor layer thin film located between the lower dielectric layer thin film and the upper dielectric layer thin film;

[0095] The material of the lower dielectric layer film is silicon dioxide;

[0096] The material of the upper dielectric layer film is a silicon dioxide layer;

[0097] The thickness of the lower dielectric layer film and the upper dielectric layer film is 800 nm.

[0098] The semiconductor layer film is photolithographically and etched to form a plurality of ridge waveguide structures; wherein each layer of the semiconductor layer film surrounds the ridge waveguide structure of the layer.

[0099] The materials of the semiconductor layer thin film include silicon nitride, amorphous silicon and gallium arsenide;

[0100] Wherein, the method for preparing the semiconductor layer thin film further comprises: forming a coating layer on the surface of the thin film structure;

[0101] Specifically:

[0102] The substrate formed with the thin film structure is placed in a chamber filled with oxygen plasma, so that the oxygen plasma oxidizes the thin film structure to form the coating layer.

[0103] The steps of photolithography and etching the semiconductor layer film include:

[0104] forming a first mask layer on the semiconductor layer film, wherein the first mask layer includes a plurality of grooves;

[0105] forming the upper dielectric layer thin film on the first mask layer;

[0106] forming a second mask layer on the upper dielectric film;

[0107] Etching the second mask layer to form a plurality of openings;

[0108] Using the etched second mask layer as a mask, etching the upper dielectric layer film and the semiconductor layer film to form the ridge waveguide structure;

[0109] The second mask layer is removed, and a third mask layer is formed on the surface of the upper dielectric layer film and the ridge waveguide structure after the second mask layer is removed, wherein the third mask layer includes a plurality of grooves;

[0110] Using the first mask layer and the third mask layer as masks, etching the upper dielectric layer film and the semiconductor layer film to form the lower dielectric layer film;

[0111] The first mask layer and the third mask layer are removed.

[0112] Through simulation experiments, a comparison table is obtained;

[0113] Table 1: Experimental data of filters prepared by different methods

[0114] Performance Indicators Prior art Example 1 Example 2 Central wavelength 1550nm 1550nm 1550nm bandwidth 20nm 10nm 12nm Insertion loss 1.5dB 0.5dB 0.7dB Isolation 20dB 30dB 28dB Temperature stability 20℃ 60℃ 55℃

[0115] Compared with the prior art, Example 1 and Example 2 provide a narrower bandwidth at the same central wavelength, and the two groups of insertion losses are significantly smaller than the prior art. Higher isolation reduces interference between different signals. Example 1 and Example 2 maintain stable performance over a wider temperature range.

[0116] In summary, by designing a multilayer thin film structure, including a lower dielectric layer, an upper dielectric layer and a semiconductor layer, the propagation path and phase delay of light waves can be precisely controlled, thereby achieving selective transmission of specific wavelengths. Secondly, the multilayer thin film structure can achieve selective transmission of light of specific wavelengths by precisely controlling the thickness of each layer of the film and the refractive index of the material, which is crucial for applications that require precise wavelength control, such as optical communications and spectral analysis. Finally, due to the settings of ridge waveguides and tapered waveguides, the propagation path and mode of light can be further precisely controlled.

[0117] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for manufacturing a filter, characterized in that: The following steps are included: preparing a substrate; forming a buried layer on the substrate; forming an insulating layer on the buried layer; forming a multi-layer thin film structure on the insulating layer; Wherein, forming each layer of the thin film structure includes forming a lower dielectric layer thin film, an upper dielectric layer thin film, and a semiconductor layer thin film located between the lower dielectric layer thin film and the upper dielectric layer thin film; The semiconductor layer film is photolithographically and etched to form a plurality of ridge waveguide structures; wherein each layer of the semiconductor layer film surrounds the ridge waveguide structure of the layer.

2. The method for manufacturing a filter according to claim 1, characterized in that: The multi-layer film structure includes a third film layer; By etching the semiconductor layer film in the third film layer, a ridge waveguide structure is formed as an output tapered waveguide and an input tapered waveguide on the substrate.

3. The method for manufacturing a filter according to claim 2, wherein: The buried layer includes at least one of a silicon dioxide layer, a phosphosilicate glass layer, and a silicon carbide layer.

4. The method for manufacturing a filter according to claim 3, characterized in that: The insulating layer includes a silicon dioxide layer.

5. The method for manufacturing a filter according to claim 4, characterized in that: The material of the semiconductor layer thin film includes at least one of silicon nitride, amorphous silicon, gallium arsenide, indium phosphide, and nanocrystal; Wherein, when the material of the semiconductor layer thin film includes silicon nitride, the preparation method further includes: forming a coating layer on the surface of the thin film structure; Specifically: The substrate formed with the thin film structure is placed in a chamber filled with oxygen plasma, so that the oxygen plasma oxidizes the thin film structure to form the coating layer.

6. The method for manufacturing a filter according to claim 5, characterized in that: The material of the lower dielectric layer film is silicon dioxide; The material of the upper dielectric layer thin film is at least one of a silicon dioxide layer and a silicon nitride layer; The thickness of the lower dielectric layer film and the upper dielectric layer film is 800nm-1200nm.

7. The method for manufacturing a filter according to claim 6, characterized in that: The substrate is at least one of a semiconductor substrate and a first dielectric layer; Wherein, when the substrate is a semiconductor base, the material of the semiconductor base includes at least one of silicon, gallium arsenide, gallium nitride, doped silicon, and doped silicon carbide; When the substrate is a semiconductor base and a first dielectric layer, the material of the semiconductor base includes silicon, gallium arsenide, gallium nitride, and aluminum nitride; and the material of the first dielectric layer is silicon dioxide.

8. The method for manufacturing a filter according to claim 7, characterized in that: The multilayer film structure comprises N layers of film structure, wherein N is a positive integer and N≥2; The method for preparing the multilayer thin film structure also includes: before forming the i-th thin film structure, forming a covering layer covering the i-1th thin film structure on the i-1th thin film structure, and the covering layer is a silicon dioxide layer to isolate the i-th thin film structure from the i-1th thin film structure, so that the i-th thin film structure and the i-1th thin film structure are independent of each other.

9. The method for manufacturing a filter according to claim 8, characterized in that: The steps of photolithography and etching the semiconductor layer film include: forming a first mask layer on the semiconductor layer film, wherein the first mask layer includes a plurality of grooves; forming the upper dielectric layer thin film on the first mask layer; forming a second mask layer on the upper dielectric film; Etching the second mask layer to form a plurality of openings; Using the etched second mask layer as a mask, etching the upper dielectric layer film and the semiconductor layer film to form the ridge waveguide structure; The second mask layer is removed, and a third mask layer is formed on the surface of the upper dielectric layer film and the ridge waveguide structure after the second mask layer is removed, wherein the third mask layer includes a plurality of grooves; Using the first mask layer and the third mask layer as masks, etching the upper dielectric layer film and the semiconductor layer film to form the lower dielectric layer film; The first mask layer and the third mask layer are removed.

10. A filter, wherein the filter is manufactured by the filter manufacturing method according to any one of claims 1 to 9.

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