Preparation method for realizing detection function based on LNOI platform

Abstract

The invention discloses a preparation method for realizing a detection function based on an LNOI platform, and the method comprises the steps: preparing an LNOI wafer which is sequentially provided with an LN layer, a first silicon oxide layer, a first silicon layer, a second silicon oxide layer and a second silicon layer from the top to the bottom; carrying out organic and inorganic cleaning and metal mask plating on the LNOI wafer; sequentially etching the LN layer and the first silicon oxide layer of the LNOI wafer from top to bottom to the first silicon layer; cleaning the etched LNOI wafer, introducing germane gas through epitaxial growth equipment, and epitaxially forming a germanium film on the first silicon layer through a selective epitaxial process; a germanium window is formed in the LNOI wafer, phosphorus atoms are injected into the germanium window, and P-type germanium is generated after annealing treatment; silicon oxide is deposited, an electrode window of germanium and an electrode window of silicon are formed, a metal electrode is deposited, and manufacturing of the germanium detector is completed; the method has the advantage that a detection function is added on the LNOI wafer.

Description

Technical Field

[0001] The present invention relates to the technical field of detector preparation based on LNOI platform, and in particular to a preparation method for realizing a detection function based on LNOI platform. Background Art

[0002] Lithium niobate material is an ideal electro-optic modulator material. The linear electro-optic effect in lithium niobate is based on the polarization process of lithium niobate material under the action of an electric field. Electro-optic modulators based on lithium niobate have extremely high theoretical bandwidth limits. It has been widely used and verified in fields such as optical communications and microwave photonics. In recent years, thin-film lithium niobate on insulator (LNOI) materials have been prepared by thin-filming lithium niobate bulk materials and bonding them to silicon substrates. LNOI combines the advantages of high-performance photonic materials and integrated photonics, making it possible to prepare small-size, high-speed photonic devices and high-performance acousto-optic coupling devices based on LNOI. These advantages make it a highly competitive new generation of photonic integration platforms and have become a research hotspot worldwide.

[0003] Photonic integrated platforms require key components such as waveguides, modulators, and detectors. However, thin-film lithium niobate materials can only be used to make waveguides and modulators, but not detectors.

[0004] Therefore, the present invention provides a preparation method for realizing detection function based on LNOI platform, which can solve the above problems. Summary of the invention

[0005] The technical problem to be solved by the present invention is that thin-film lithium niobate materials can only be used to make waveguides and modulators, but cannot be used to make detectors. Therefore, a preparation method for realizing a detection function based on a LNOI platform is provided. The preparation method for realizing a detection function based on a LNOI platform comprises: Prepare an LNOI wafer, wherein the LNOI wafer is provided with an LN layer, a first silicon oxide layer, a first silicon layer, a second silicon oxide layer, and a second silicon layer in sequence from top to bottom; Perform organic and inorganic cleaning and metal mask coating on LNOI wafers; The LNOI wafer is etched from top to bottom in sequence from the LN layer and the first silicon oxide layer to the first silicon layer; The etched LNOI wafer is cleaned, germanium gas is introduced through the epitaxial growth equipment, and a germanium film is epitaxially grown on the first silicon layer through a selective epitaxial process; After the germanium film epitaxy is completed, a germanium window is opened on the LNOI wafer, phosphorus atoms are injected into the germanium window, and after annealing, P-type germanium is generated; Silicon oxide is deposited, and after the silicon oxide deposition is completed, a germanium electrode window and a silicon electrode window are opened, and a metal electrode is deposited to complete the production of a germanium detector.

[0006] Furthermore, the specific process of performing organic and inorganic cleaning on the LNOI wafer includes: Using high-energy sound waves to remove dirt and particles from the surface of LNOI wafers; Performing a first-stage cleaning of the LNOI wafer using a first cleaning solution; The LNOI wafers were cleaned in a second stage using an organic solution.

[0007] Furthermore, the first cleaning solution includes SPM solution and SC1 solution.

[0008] Furthermore, the organic solution is vinyl chloride resin.

[0009] Furthermore, the specific process of coating the LNOI wafer with a metal mask includes: Design and produce photomasks with wafer etching patterns; Using a photomask, photolithography is performed on the LNOI wafer through photoresist to form a photoresist pattern; Depositing a metal seed layer on the wafer surface after photolithography by physical vapor deposition method; Stripping off the unselected seed layer and excess photoresist to form an LNOI wafer with a patterned seed layer; By electrochemical deposition technology, metal is deposited on the seed layer on the LNOI wafer with the patterned seed layer to form a metal mask.

[0010] Further, the etching of the LN layer and the first silicon oxide layer to the first silicon layer from top to bottom of the LNOI wafer in sequence includes: Uniformly apply photoresist to the LNOI wafer on which the metal mask is formed; Expose the photoresist on the LNOI wafer using a photolithography machine; After exposure, the LNOI wafer is placed in the developer; Using a plasma etcher to sequentially etch the LN layer and the first silicon oxide layer of the LNOI wafer, wherein the first silicon oxide layer is etched to a thickness of 50 nm; The first silicon oxide layer is rinsed with a hydrofluoric acid solution.

[0011] Furthermore, the cleaning of the etched LNOI wafer includes: using HF solution and RCA solution to clean the etched LNOI wafer.

[0012] The implementation of the present invention has the following beneficial effects: The present invention proposes to selectively grow germanium detector materials on the LNOI platform to make a germanium PIN detector, thereby solving the shortcoming of the LNOI platform that cannot be detected. Thus, the functions of optical transmission, modulation and detection on the LNOI platform are realized, greatly expanding the application field of the LNOI platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A flow chart of a preparation method for realizing detection function based on the LNOI platform provided by the present invention; Figure 2 It is a schematic flow chart of the structure of the present invention. DETAILED DESCRIPTION The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example

[0014] Please refer to the instruction manual Figure 1-2 This embodiment provides a preparation method for realizing a detection function based on an LNOI platform, and the preparation method for realizing a detection function based on an LNOI platform includes: Prepare an LNOI wafer, wherein the LNOI wafer is provided with an LN layer, a first silicon oxide layer, a first silicon layer, a second silicon oxide layer and a second silicon layer in sequence from top to bottom; wherein the first silicon layer is an N-type heavily doped layer; Perform organic and inorganic cleaning and metal mask coating on LNOI wafers; The LNOI wafer is etched from top to bottom in sequence from the LN layer and the first silicon oxide layer to the first silicon layer; The etched LNOI wafer is cleaned, germanium gas is introduced through the epitaxial growth equipment, and a germanium film is epitaxially grown on the first silicon layer through a selective epitaxial process; After the germanium film epitaxy is completed, a germanium window is opened on the LNOI wafer, phosphorus atoms are injected into the germanium window, and after annealing, P-type germanium is generated; Silicon oxide is deposited, and after the silicon oxide deposition is completed, a germanium electrode window and a silicon electrode window are opened, and a metal electrode is deposited to complete the production of a germanium detector.

[0015] The specific process of organic and inorganic cleaning of LNOI wafers includes: Using high-energy sound waves to remove dirt and particles from the surface of LNOI wafers; Performing a first-stage cleaning of the LNOI wafer using a first cleaning solution; The LNOI wafers were cleaned in a second stage using an organic solution.

[0016] The specific process of coating the LNOI wafer with a metal mask includes: Design and produce photomasks with wafer etching patterns; Using a photomask, photolithography is performed on the LNOI wafer through photoresist to form a photoresist pattern; Depositing a metal seed layer on the wafer surface after photolithography by physical vapor deposition method; Stripping off the unselected seed layer and excess photoresist to form an LNOI wafer with a patterned seed layer; By electrochemical deposition technology, metal is deposited on the seed layer on the LNOI wafer with the patterned seed layer to form a metal mask.

[0017] The etching of the LN layer and the first silicon oxide layer to the first silicon layer from top to bottom of the LNOI wafer comprises: Uniformly apply photoresist to the LNOI wafer on which the metal mask is formed; Expose the photoresist on the LNOI wafer using a photolithography machine; After exposure, the LNOI wafer is placed in the developer; Using a plasma etcher to sequentially etch the LN layer and the first silicon oxide layer of the LNOI wafer, wherein the first silicon oxide layer is etched to a thickness of 50 nm; The first silicon oxide layer is rinsed. Example

[0018] Please refer to the instruction manual Figure 1-2 This embodiment provides a preparation method for realizing a detection function based on an LNOI platform, and the preparation method for realizing a detection function based on an LNOI platform includes: Prepare an LNOI wafer, wherein the LNOI wafer is provided with an LN layer, a first silicon oxide layer, a first silicon layer, a second silicon oxide layer and a second silicon layer in sequence from top to bottom; wherein the first silicon layer is an N-type heavily doped layer; Perform organic and inorganic cleaning and metal mask coating on LNOI wafers; The LNOI wafer is etched from top to bottom in sequence from the LN layer and the first silicon oxide layer to the first silicon layer; The etched LNOI wafer is cleaned, germanium gas is introduced through the epitaxial growth equipment, and a germanium film is epitaxially grown on the first silicon layer through a selective epitaxial process; After the germanium film epitaxy is completed, a germanium window is opened on the LNOI wafer, phosphorus atoms are injected into the germanium window, and after annealing, P-type germanium is generated; Silicon oxide is deposited, and after the silicon oxide deposition is completed, a germanium electrode window and a silicon electrode window are opened, and a metal electrode is deposited to complete the production of a germanium detector.

[0019] The specific process of organic and inorganic cleaning of LNOI wafers includes: Using high-energy sound waves to remove dirt and particles from the surface of LNOI wafers; Performing a first-stage cleaning of the LNOI wafer using a first cleaning solution; The LNOI wafers were cleaned in a second stage using an organic solution.

[0020] The first cleaning solution includes SPM solution and SC1 solution.

[0021] The organic solution is vinyl chloride resin.

[0022] The specific process of coating the LNOI wafer with a metal mask includes: Design and produce photomasks with wafer etching patterns; Using a photomask, photolithography is performed on the LNOI wafer through photoresist to form a photoresist pattern; Depositing a metal seed layer on the wafer surface after photolithography by physical vapor deposition method; Stripping off the unselected seed layer and excess photoresist to form an LNOI wafer with a patterned seed layer; By electrochemical deposition technology, metal is deposited on the seed layer on the LNOI wafer with the patterned seed layer to form a metal mask.

[0023] The etching of the LN layer and the first silicon oxide layer to the first silicon layer from top to bottom of the LNOI wafer comprises: Uniformly apply photoresist to the LNOI wafer on which the metal mask is formed; Expose the photoresist on the LNOI wafer using a photolithography machine; After exposure, the LNOI wafer is placed in the developer; Using a plasma etcher to sequentially etch the LN layer and the first silicon oxide layer of the LNOI wafer, wherein the first silicon oxide layer is etched to a thickness of 50 nm; The first silicon oxide layer is rinsed with a hydrofluoric acid solution.

[0024] The cleaning of the etched LNOI wafer includes: using HF solution and RCA solution to clean the etched LNOI wafer.

[0025] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method for realizing detection function based on LNOI platform, It is characterized in that include: Prepare an LNOI wafer, wherein the LNOI wafer is provided with an LN layer, a first silicon oxide layer, a first silicon layer, a second silicon oxide layer and a second silicon layer in sequence from top to bottom; wherein the first silicon layer is an N-type heavily doped layer; Perform organic and inorganic cleaning and metal mask coating on LNOI wafers; The LNOI wafer is etched from top to bottom in sequence from the LN layer and the first silicon oxide layer to the first silicon layer; The etched LNOI wafer is cleaned, germanium gas is introduced through the epitaxial growth equipment, and a germanium film is epitaxially grown on the first silicon layer through a selective epitaxial process; After the germanium film epitaxy is completed, a germanium window is opened on the LNOI wafer, phosphorus atoms are injected into the germanium window, and after annealing, P-type germanium is generated; Silicon oxide is deposited, and after the silicon oxide deposition is completed, a germanium electrode window and a silicon electrode window are opened, and a metal electrode is deposited to complete the production of a germanium detector.

2. The preparation method for realizing detection function based on LNOI platform according to claim 1, It is characterized in that The specific process of organic and inorganic cleaning of LNOI wafers includes: Using high-energy sound waves to remove dirt and particles from the surface of LNOI wafers; Performing a first-stage cleaning of the LNOI wafer using a first cleaning solution; The LNOI wafers were cleaned in a second stage using an organic solution.

3. The preparation method for realizing detection function based on LNOI platform according to claim 2, It is characterized in that The first cleaning solution includes SPM solution and SC1 solution.

4. The preparation method for realizing detection function based on LNOI platform according to claim 3, It is characterized in that The organic solution is vinyl chloride resin.

5. The preparation method for realizing detection function based on LNOI platform according to claim 4, It is characterized in that The specific process of coating the LNOI wafer with a metal mask includes: Design and produce photomasks with wafer etching patterns; Using a photomask, photolithography is performed on the LNOI wafer through photoresist to form a photoresist pattern; Depositing a metal seed layer on the wafer surface after photolithography by physical vapor deposition method; Stripping off the unselected seed layer and excess photoresist to form an LNOI wafer with a patterned seed layer; By electrochemical deposition technology, metal is deposited on the seed layer on the LNOI wafer with the patterned seed layer to form a metal mask.

6. The preparation method for realizing detection function based on LNOI platform according to claim 5, It is characterized in that The etching of the LN layer and the first silicon oxide layer to the first silicon layer from top to bottom of the LNOI wafer comprises: Uniformly apply photoresist to the LNOI wafer on which the metal mask is formed; Expose the photoresist on the LNOI wafer using a photolithography machine; After exposure, the LNOI wafer is placed in the developer; Using a plasma etcher to sequentially etch the LN layer and the first silicon oxide layer of the LNOI wafer, wherein the first silicon oxide layer is etched to a thickness of 50 nm; The first silicon oxide layer is rinsed using a hydrofluoric acid solution.

7. The preparation method for realizing detection function based on LNOI platform according to claim 6, It is characterized in that The cleaning of the etched LNOI wafer includes: using HF solution and RCA solution to clean the etched LNOI wafer.

Images