Special spin-drying method for cleaning gallium antimonide substrate

Abstract

The invention discloses a spin-drying method special for cleaning a gallium antimonide substrate, and relates to the technical field of semiconductor materials, and the spin-drying method specifically comprises the following steps: A1, cleaning the surface of the gallium antimonide substrate by liquid medicine: fixing a wafer to be cleaned by using a special clamp, and cleaning the wafer in a beaker filled with cleaning liquid after the wafer is fixed, the clamp needs to be uniformly shaken in the liquid medicine cleaning process, so that the cleaning liquid uniformly cleans the surface, and after liquid medicine cleaning is completed, the hydrophobic condition is concerned; a2, deionized water spray cleaning is conducted on the surface of the gallium antimonide substrate, after liquid medicine cleaning is completed, the deionized water is rapidly used for spray cleaning, it is guaranteed that the deionized water evenly flushes the surface of the wafer in the spray cleaning process, after deionized water cleaning is completed, the hydrophobic condition is concerned, and through linkage control of an automatic spray device and a nitrogen purging device, the surface of the gallium antimonide substrate is cleaned; and in combination with a multi-step cleaning procedure, residual chemicals, particulate pollutants and sub-defects on the surface are effectively removed, so that the surface of the substrate reaches the high-quality standard of no smudginess and no residue.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor materials, in particular to a special drying method for cleaning gallium antimonide substrates. Background Art

[0002] Gallium antimonide (GaSb) is a Group III-V compound semiconductor, a zinc blende, and a direct bandgap material with a band gap of 0.725 eV and a lattice constant of 0.60959 nm. GaSb has excellent physical and chemical properties and is often used as a substrate material.

[0003] According to the patent title: A gallium antimonide surface cleaning liquid and a gallium antimonide substrate cleaning method (patent publication number: CN118146889A, patent publication date: 2024-06-07), the gallium antimonide surface cleaning liquid is obtained by mixing a detergent and water, the mass ratio of the detergent to water is (8-15):8, and the detergent is selected from one or more of ammonium hydroxide, ethanol, alcohol ether, acetone and isopropyl alcohol. The gallium antimonide surface cleaning liquid has high stability, no hydrophobic phenomenon occurs during the gallium antimonide cleaning process, and has a good effect on removing dirt and particle residues on the gallium antimonide surface without color difference. In addition, the cleaning method is simple, the cleaning time is short, the cleaning efficiency is high, and it has good application prospects.

[0004] However, the existing spin-drying method for cleaning gallium antimonide substrates based on the above-mentioned prior art still has the following problems: the surface of the gallium antimonide substrate is chemically active and easily oxidized and easily adsorbs chemical components. An oxide layer several nanometers thick can quickly form on the fresh surface in the air. During the spin-drying process, some substrates may become dirty, contain residual chemicals, and have sub-defects. Therefore, production requirements cannot be met. Therefore, the present invention provides a spin-drying method for cleaning gallium antimonide substrates. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention provides a dedicated spin-drying method for cleaning gallium antimonide substrates. This method solves the following problems existing in existing spin-drying methods for cleaning gallium antimonide substrates: the surface of gallium antimonide substrates has active chemical properties and is easily oxidized and easily adsorbs chemical components. In fresh air, an oxide layer several nanometers thick can quickly form on the surface. During the spin-drying process, dirt, chemical residues, and sub-defects may appear on some substrates, making it impossible to meet production requirements.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a special drying method for cleaning gallium antimonide substrates, specifically comprising the following steps:

[0007] A1. Liquid cleaning of the GaSb substrate surface: Secure the wafer to be cleaned with a special fixture. After securing, place it in a beaker filled with cleaning solution for cleaning. During the liquid cleaning process, shake the fixture evenly to ensure that the cleaning solution evenly cleans the surface. After the liquid cleaning is completed, pay attention to the hydrophobicity.

[0008] A2, Deionized water spray cleaning of the GaSb substrate surface: After the liquid cleaning is completed, it is quickly sprayed with deionized water to ensure that the deionized water evenly rinses the wafer surface. After the deionized water cleaning is completed, pay attention to the hydrophobicity;

[0009] A3, GaSb substrate spin dryer with nitrogen purge and drying: After the wafer surface is spray cleaned, the substrate is placed in the spin dryer fixture, the substrate cleaning fixture is removed, and the spin dryer is used for nitrogen purge and drying;

[0010] A4, GaSb substrate surface inspection: Use a strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection using a metallographic microscope;

[0011] A5, according to different program tests, after multiple tests, the use program of the spin dryer is matched, which effectively solves the problem of dirt, chemical residue and sub-defects on some substrates during the substrate drying process.

[0012] Preferably, in A3, the drying process of the drying machine includes the following steps:

[0013] B1: Run at 500 rpm for 5 seconds, with the flushing function turned on and the nitrogen purge function turned off;

[0014] B2: Run at 2000 rpm for 5 seconds, with water flushing and nitrogen purge functions enabled at the same time;

[0015] B2. Run at 4000 rpm for 10 seconds, turn off the flushing function and turn on the nitrogen purge function;

[0016] B2. Run at 4000 rpm for 50 seconds, and turn off the flushing and nitrogen purge functions.

[0017] Preferably, in B1, the flushing is deionized water spraying, the spraying pressure is 0.1-0.3 MPa, and the spraying time is 5-15 seconds.

[0018] Preferably, in B1, the nitrogen flow rate of the nitrogen purge is 10-20 L / min, and the purge temperature is 25-35°C.

[0019] Preferably, in A1, the cleaning liquid is prepared by mixing at least one of ammonium hydroxide, ethanol, and acetone with water in a mass ratio of 8-15 to 8.

[0020] Preferably, in the A4, the illumination intensity of the strong light is 400,000 LUX, and the magnification of the metallographic microscope is 200-1000 times.

[0021] Preferably, in A5, the spin dryer program is implemented by a programmable controller, which supports writing and switching of multiple sets of parameter combinations.

[0022] Preferably, in the above A3, the spin dryer is equipped with an automatic spraying device and a nitrogen purge device, which are started and stopped synchronously with the speed through linkage control.

[0023] The present invention provides a dedicated spin-drying method for cleaning gallium antimonide substrates. Compared with the prior art, it has the following advantages:

[0024] 1. This dedicated drying method for cleaning gallium antimonide substrates effectively removes surface residual agents, particulate contaminants, and sub-defects through the linkage control of an automatic spray device and a nitrogen purge device, combined with a multi-step cleaning procedure (such as deionized water spraying, nitrogen purge and drying), ensuring that the substrate surface meets high-quality standards without dirt or residue.

[0025] 2. This special spin-drying method for cleaning gallium antimonide substrates uses a programmable controller to support multiple parameter combinations (such as speed, time, flushing / purge start and stop). The spin-drying program can be flexibly adjusted according to different production needs, reducing manual intervention, avoiding operational errors, and improving process repeatability.

[0026] 3. This special drying method for cleaning GaSb substrates significantly shortens the exposure time of GaSb substrates to air through rapid drying (high speed 4000 rpm) and inert environment protection of nitrogen purge, reduces the risk of oxidation and chemical adsorption, and ensures the stability of the chemical properties of the substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of the method of the present invention;

[0028] Figure 2 This is a comparative experimental result diagram of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0030] See also Figure 1-Figure 2 , the present invention provides a technical solution:

[0031] A special drying method for cleaning gallium antimonide substrates includes the following steps:

[0032] A1. Liquid cleaning of the GaSb substrate surface: Secure the wafer to be cleaned with a special fixture. After securing, place it in a beaker filled with cleaning solution for cleaning. During the liquid cleaning process, shake the fixture evenly to ensure that the cleaning solution evenly cleans the surface. After the liquid cleaning is completed, pay attention to the hydrophobicity.

[0033] A2, Deionized water spray cleaning of the GaSb substrate surface: After the liquid cleaning is completed, it is quickly sprayed with deionized water to ensure that the deionized water evenly rinses the wafer surface. After the deionized water cleaning is completed, pay attention to the hydrophobicity;

[0034] A3, GaSb substrate spin dryer with nitrogen purge and drying: After the wafer surface is spray cleaned, the substrate is placed in the spin dryer fixture, the substrate cleaning fixture is removed, and the spin dryer is used for nitrogen purge and drying;

[0035] A4, GaSb substrate surface inspection: Use a strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection using a metallographic microscope;

[0036] A5, according to different program tests, after multiple tests, the use program of the spin dryer is matched, which effectively solves the problem of dirt, chemical residue and sub-defects on some substrates during the substrate drying process.

[0037] After cleaning with chemical solution and spraying with deionized water, we “pay attention to the hydrophobicity”. By real-time monitoring of changes in surface hydrophobicity, we adjust process parameters in a timely manner to prevent subsequent defects caused by incomplete cleaning.

[0038] Production process:

[0039]

[0040]

[0041] According to the experimental verification program, the strong light and microscope inspections all meet the qualified standards. The test results are as follows Figure 2 As shown, after two weeks of experimentation in Example 6, the manufacturing process of this embodiment is stable and meets the production requirements.

[0042] In this embodiment, in A3, the drying process of the drying machine includes the following steps:

[0043] B1: Run at 500 rpm for 5 seconds, with the flushing function turned on and the nitrogen purge function turned off;

[0044] B2: Run at 2000 rpm for 5 seconds, with water flushing and nitrogen purge functions enabled at the same time;

[0045] B3. Run at 4000 rpm for 10 seconds, turn off the flushing function and turn on the nitrogen purge function;

[0046] B4. Run at 4000 rpm for 50 seconds, and turn off the flushing and nitrogen purge functions.

[0047] By adjusting the spin dryer speed in stages and simultaneously turning on / off the nitrogen purge function, efficient removal of residual droplets is achieved, avoiding the residual reagents caused by insufficient centrifugal force in the early stage of high-speed drying. At the same time, nitrogen purge inhibits the formation of the oxide layer and reduces surface sub-defects.

[0048] Finally, spin dry at 4000 rpm for 50 seconds to completely remove surface moisture and particles, ensure uniform drying of the substrate, and solve the problem of dirt and residue.

[0049] In this embodiment, in B1 and B2, the flushing water is sprayed with deionized water, the spraying pressure is 0.1-0.3 MPa, and the spraying time is 5-15 seconds.

[0050] Precise control of the spray pressure (0.1-0.3MPa) and spray time (5-15 seconds) ensures that deionized water quickly covers the wafer surface, flushes away residual liquid, and prevents hydrophobicity caused by local drying.

[0051] In this embodiment, in B2 and B4, the nitrogen flow rate of the nitrogen purge is 10-20 L / min, and the purge temperature is 25-35°C.

[0052] The settings of nitrogen flow rate (10-20L / min) and temperature (25-35℃) can not only effectively purge the surface liquid film, but also avoid damage to the chip surface due to excessive temperature or excessive airflow.

[0053] In this embodiment, in the A1, the cleaning liquid is prepared by mixing at least one of ammonium hydroxide, ethanol, and acetone with water in a mass ratio of 8-15 to 8.

[0054] The cleaning solution is a mixture of ammonium hydroxide, ethanol, acetone, etc. and water in a ratio of 8-15:8. It has both detergency and low corrosiveness, reduces chemical erosion on the surface of gallium antimonide, avoids hydrophobicity, and improves cleaning uniformity.

[0055] In this embodiment, in the A4, the illumination intensity of the strong light is 400,000 LUX, and the magnification of the metallographic microscope is 200-1000 times.

[0056] The combined inspection of a strong light (400,000 LUX) and a metallographic microscope (200-1000 times) can quickly detect tiny surface defects (such as scratches and residual particles), ensuring that the substrate reaches high cleanliness standards after cleaning.

[0057] In this embodiment, in A5, the spin dryer program is implemented by a programmable controller, which supports writing and switching of multiple groups of parameter combinations.

[0058] The spin dryer program uses a programmable controller to achieve flexible switching of multiple parameter combinations to adapt to different batch or process requirements and improve production efficiency and consistency.

[0059] The linkage control of automatic spraying and nitrogen purge device ensures synchronization of operation and speed, reduces human intervention errors and guarantees process stability.

[0060] In this embodiment, in the A3, the spin dryer is equipped with an automatic spraying device and a nitrogen purge device, which are started and stopped synchronously with the speed through linkage control.

[0061] Comparative Example:

[0062] Example 1:

[0063] Deionized water spray drying: After the wafer surface is spray-cleaned, remove the fixture and place it on the spin dryer. After starting, it will automatically spray for 10 seconds (500 rpm) while rotating. After the spraying is completed, it will be directly dried for 40 seconds (4000 rpm);

[0064] Substrate surface inspection: Use 400,000 LUX strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection with a metallographic microscope; the inspection results are as follows Figure 2 As shown;

[0065] Production process:

[0066] process Time S Speed ​​r flush Blow 1 10 500 Open closure 2 40 4000 closure closure

[0067] Comparative Example:

[0068] Example 2:

[0069] Nitrogen purge and spin-drying: After the wafer surface is spray-cleaned, remove the fixture and place it on the spin dryer. After starting, it will automatically purge nitrogen for 10 seconds (2000 rpm) while rotating. After the purge is completed, it will be directly dried for 40 seconds (4000 rpm);

[0070] Substrate surface inspection: Use 400,000 LUX strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection with a metallographic microscope; the inspection results are as follows Figure 2 As shown;

[0071] Production process:

[0072] process Time S Speed ​​r flush Blow 1 10 2000 closure Open 2 40 4000 closure closure

[0073] Example 3:

[0074] Spray first, then nitrogen purge and dry: After the wafer surface is spray-cleaned, remove the fixture and place it on the spin dryer. After starting, rotate and automatically rinse with deionized water for 10 seconds (500 rpm), and then spin dry for 40 seconds (4000 rpm) after nitrogen purge.

[0075] Substrate surface inspection: Use 400,000 LUX strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection with a metallographic microscope; the inspection results are as follows Figure 2 As shown;

[0076] Production process:

[0077]

[0078]

[0079] Example 4:

[0080] Deionized water spray drying: After the wafer surface is spray-cleaned, remove the fixture and place it on the spin dryer. After starting, it will automatically spray for 10 seconds (500 rpm) while rotating. After the spraying is completed, it will be directly dried for 60 seconds (4000 rpm);

[0081] Substrate surface inspection: Use 400,000 LUX strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection with a metallographic microscope; the inspection results are as follows Figure 2 As shown;

[0082] Production process:

[0083]

[0084] Example 5:

[0085] Nitrogen purge and spin-drying: After the wafer surface is spray-cleaned, remove the fixture and place it on the spin dryer. After starting, it will automatically purge nitrogen for 10 seconds (2000 rpm) while rotating. After the purge is completed, it will be directly dried for 60 seconds (4000 rpm);

[0086] Substrate surface inspection: Use 400,000 LUX strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection with a metallographic microscope; the inspection results are as follows Figure 2 As shown;

[0087] Production process:

[0088] process Time S Speed ​​r flush Blow 1 10 2000 closure Open 2 60 4000 closure closure

[0089] Through verification, it can be seen that the use of the special spin dryer technology method for cleaning gallium antimonide substrates of the present invention can improve the surface quality of gallium antimonide substrates, and effectively solve the problems of dirt, chemical residues and sub-defects on some substrates, which is fully compatible with production.

[0090] In summary, the surface of the gallium antimonide substrate is cleaned with chemical liquid: the wafer to be cleaned is fixed with a special clamp, and after the fixation is completed, it is placed in a beaker filled with cleaning liquid for cleaning. The clamp needs to be shaken evenly during the chemical liquid cleaning process to ensure that the cleaning liquid evenly cleans the surface. After the chemical liquid cleaning is completed, pay attention to the hydrophobicity. The surface of the gallium antimonide substrate is sprayed with deionized water: after the chemical liquid cleaning is completed, it is quickly sprayed with deionized water. The spraying and rinsing process ensures that the deionized water evenly rinses the surface of the wafer. After the deionized water cleaning is completed, pay attention to the hydrophobicity. The gallium antimonide substrate spin dryer is nitrogen purged and dried: after the wafer surface is sprayed and cleaned, the clamp is removed and the spin dryer is used for nitrogen purge function for drying. The surface inspection of the gallium antimonide substrate: a strong light is used to complete the preliminary surface inspection of the cleaned gallium antimonide wafer, and finally the surface inspection is completed by a metallographic microscope. According to different program tests, the dryer usage program is matched after multiple tests, which effectively solves the problem of dirt, chemical residue and sub-defects on some substrates during the substrate drying process.

[0091] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0092] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A special drying method for cleaning gallium antimonide substrates, characterized by: The specific steps include: A1. Liquid cleaning of the GaSb substrate surface: Secure the wafer to be cleaned with a special fixture. After securing, place it in a beaker filled with cleaning solution for cleaning. During the liquid cleaning process, shake the fixture evenly to ensure that the cleaning solution evenly cleans the surface. After the liquid cleaning is completed, pay attention to the hydrophobicity. A2, Deionized water spray cleaning of the GaSb substrate surface: After the liquid cleaning is completed, it is quickly sprayed with deionized water to ensure that the deionized water evenly rinses the wafer surface. After the deionized water cleaning is completed, pay attention to the hydrophobicity; A3, GaSb substrate spin dryer with nitrogen purge and drying: After the wafer surface is spray cleaned, the substrate is placed in the spin dryer fixture, the substrate cleaning fixture is removed, and the spin dryer is used for nitrogen purge and drying; A4, GaSb substrate surface inspection: Use a strong light to complete the preliminary surface inspection of the cleaned GaSb wafer, and finally complete the surface inspection using a metallographic microscope; A5, according to different program tests, after multiple tests, the use program of the spin dryer is matched, which effectively solves the problem of dirt, chemical residue and sub-defects on some substrates during the substrate drying process.

2. The method for cleaning gallium antimonide substrates according to claim 1, characterized in that: In A3, the drying process of the drying machine includes the following steps: B1: Run at 500 rpm for 5 seconds, with the flushing function turned on and the nitrogen purge function turned off; B2: Run at 2000 rpm for 5 seconds, with water flushing and nitrogen purge functions enabled at the same time; B2. Run at 4000 rpm for 10 seconds, turn off the flushing function and turn on the nitrogen purge function; B2. Run at 4000 rpm for 50 seconds, and turn off the flushing and nitrogen purge functions.

3. The method for cleaning gallium antimonide substrates according to claim 2, wherein: In the above-mentioned B1, the flushing is performed by spraying deionized water, the spraying pressure is 0.1-0.3 MPa, and the spraying time is 5-15 seconds.

4. The method for cleaning gallium antimonide substrates according to claim 2, wherein: In the above-mentioned B1, the nitrogen flow rate of nitrogen purge is 10-20 L / min, and the purge temperature is 25-35°C.

5. The method for drying gallium antimonide substrates according to claim 1, wherein: In the above-mentioned A1, the cleaning liquid is prepared by mixing at least one of ammonium hydroxide, ethanol, and acetone with water in a mass ratio of 8-15 to 8.

6. The spin-drying method for cleaning gallium antimonide substrates according to claim 1, characterized in that: In the A4, the illumination intensity of the strong light is 400,000 LUX, and the magnification of the metallographic microscope is 200-1000 times.

7. The spin-drying method for cleaning gallium antimonide substrates according to claim 1, characterized in that: In A5, the spin dryer program is implemented by a programmable controller, which supports writing and switching of multiple groups of parameter combinations.

8. The spin-drying method for cleaning gallium antimonide substrates according to claim 1, characterized in that: In the A3, the spin dryer is equipped with an automatic spray device and a nitrogen purge device, which are started and stopped synchronously with the speed through linkage control.

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