A cleaning method for improving the cleanliness of the polished surface of a large array infrared detector

Abstract

The invention provides a cleaning method for improving the cleanliness of the surface of a large-array infrared detector after polishing, and belongs to the technical field of infrared detector preparation. The method solves the problem of blind pixels increasing due to residues in a traditional cleaning process. The method comprises the following steps: washing the polished surface of an infrared detector chip by water mist before taking out the chip after polishing; after taking out the chip, placing the infrared detector chip in a cleaning tool, and scrubbing the infrared detector chip by a detergent combined with DI water; washing the surface of the infrared detector chip by DI water; scrubbing the surface of the infrared detector chip by an alkaline cleaning agent; washing the surface of the infrared detector chip by DI water; and cleaning the surface of the infrared detector chip by a combination of an organic solvent and megasonic cleaning. The method is applied to cleaning the surface of a type II superlattice infrared detector after polishing.

Description

Technical Field

[0001] The invention provides a cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector, belonging to the technical field of infrared detector preparation. Background Art

[0002] Infrared detectors have unique advantages such as high sensitivity and low false alarm rate, so they have wide application value in infrared countermeasures, thermal imaging, air monitoring and space communications. Although mercury cadmium telluride infrared detectors have advantages such as high quantum efficiency and fast response speed, and have become the most widely used infrared detectors, for long-wave and very long-wave infrared detection, mercury cadmium telluride materials have the characteristics of difficult component control, poor thickness and component uniformity, low electronic effective mass and high manufacturing cost, which makes it difficult for high-performance long-wave infrared detectors to be widely used. Therefore, new materials for infrared detectors are urgently needed to be developed.

[0003] In recent years, great progress has been made in the research of antimonide type II superlattice materials in terms of epitaxial growth and luminescence properties, laying an important foundation for obtaining high-performance infrared band optoelectronic devices. InAs / GaSb type II superlattice infrared detector chips are classified as back-incident devices according to the signal collection direction. When working at low temperatures, the infrared transmittance of the GaSb single crystal substrate is low, and a back thinning process is required to enhance the transmittance of the infrared signal. The polishing of the InAs / GaSb type II superlattice infrared detector chip is to use polishing liquid and polishing pad on a polishing machine to perform the final polishing of the substrate surface in a chemical mechanical reaction manner to improve the roughness, flatness and nanomorphology of the polished surface. Under normal circumstances, the polishing removal amount is about 10μm. After the final polishing is completed, a large amount of polishing residual liquid and process derivatives will inevitably remain on the surface of the chip. At present, the cleaning process after the final polishing of the infrared detector chip uses water mist rinsing + organic cleaning process (ie, acetone, ethanol, isopropanol), such as Figure 1 As shown in the figure, the traditional process can only remove part of the dust, large particles and the protective glue coated on the metal PAD, but the Al in the polishing residual liquid 2 O 3 Solid particles and process derivatives (Ga 2 O 3 , Sb 2 O 3 , Sb 2 O 5 ) will still adhere to the InAs / GaSbⅡ type superlattice infrared detector chip, affecting the particle performance of the cleaning process, and then affecting the chip blind pixel rate and the next anti-reflection film process. Therefore, it is necessary to study the cleaning of infrared detector chips after polishing. Summary of the invention

[0004] In order to solve the problem of increased blind pixels due to residues in traditional cleaning processes, the present invention proposes a cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector.

[0005] The technical solution adopted by the present invention is: a cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector, comprising the following steps:

[0006] Step S1: washing the polished surface of the infrared detector chip by water mist before taking out the infrared detector chip after polishing;

[0007] Step S2: After taking the chip, place the infrared detector chip in a cleaning tool, scrub the infrared detector chip with a detergent combined with DI water, and the subsequent cleaning steps S3-S5 are all cleaned on the cleaning tool;

[0008] Step S3: Rinse the surface of the infrared detector chip with DI water;

[0009] Step S4: using an alkaline cleaning agent to scrub the surface of the infrared detector chip;

[0010] Step S5: Rinse the surface of the infrared detector chip with DI water;

[0011] Step S6: Cleaning the surface of the infrared detector chip by combining organic solvent and megasonic cleaning.

[0012] Furthermore, the cleaning tool includes a sample placement table that can hold infrared detector chips of various sizes, a tweezers clamping part and a water flow trough part. The sample placement table is a groove, and a water flow trough is provided between the groove and the bottom plate of the cleaning tool. The side of the sample placement table is a tweezers clamping groove. The infrared detector chip taken out after polishing is placed in the corresponding groove according to specifications.

[0013] Furthermore, the sum of the height of the sample placement table and the height of the infrared detector chip after thinning is equal to the height of the boss on one side of the groove.

[0014] Furthermore, step S2 specifically includes:

[0015] First, DI water is overflowed onto the surface of the infrared detector chip to achieve a wetting effect;

[0016] Then use a dust-free clean finger cot, dip it in a mixture of detergent and DI water, and slowly wipe the polished surface in one direction of the infrared detector chip. Repeat the wipe 2-3 times.

[0017] Furthermore, in steps S3 and S5, washing the surface of the infrared detector chip with DI water is achieved by spraying DI water at a low speed toward the center of the infrared detector chip with a fixed nozzle.

[0018] Furthermore, the alkaline cleaning agent in step S4 is a mixed solution of sodium hydroxide solution, sodium carbonate solution, sodium hypochlorite solution, tetrasodium glutamate diacetate solution and DI water according to a set ratio.

[0019] Furthermore, in step S4, a small amount of the mixed solution is first sucked with a dropper to rinse the surface of the infrared detector chip 2-3 times, and then a new dust-free clean finger glove is put on, dipped in the mixed solution, and the polished surface is slowly wiped in one direction of the infrared detector chip for 2-3 times.

[0020] Furthermore, before cleaning in step S6, the infrared detector chip is first removed from the cleaning tool, and then the infrared detector chip is sequentially subjected to acetone megasonic cleaning, ethanol megasonic cleaning and isopropanol megasonic cleaning, and finally blown dry with N2.

[0021] Furthermore, the sample placement table includes a first chip placement table, a second chip placement table, a third chip placement table, a fourth chip placement table and a fifth chip placement table. The first chip placement table is used to place an infrared detector chip with a specification of 1280×1024 and a pixel center distance of 15um. The second chip placement table is used to place an infrared detector chip with a specification of 640×512 and a pixel center distance of 25um. The third chip placement table is used to place an infrared detector chip with a specification of 640×512 and a pixel center distance of 15um. The fourth chip placement table is used to place an infrared detector chip with a specification of 320×256 and a pixel center distance of 30um. The fifth chip placement table is used to place an infrared detector chip with a specification of 1024×1024 and a pixel center distance of 20um.

[0022] Furthermore, the infrared detector chip is a type II superlattice infrared detector chip using III-V group materials.

[0023] Compared with the prior art, the present invention has the following beneficial effects: the present invention designs a cleaning tool that matches the chip size, which is convenient for fixing the position, and adds process steps such as detergent, alkaline cleaning agent, and megasonic cleaning during the cleaning process, thereby improving the particle size performance of the chip cleaning after the final polishing. The specific advantages are as follows:

[0024] 1. The present invention designs cleaning tooling for type II superlattice infrared detector chips of different specifications, which is convenient for fixing the chip during cleaning and at the same time ensures that the chip surface is flush with the surrounding cleaning tooling plane, so that the edges and corners can be cleaned more thoroughly, thereby achieving a good cleaning effect.

[0025] 2. The present invention is designed for the cleaning process of the infrared detector chip after polishing, which can remove dirt below 0.1um and achieve chip surface cleanliness.

[0026] 3. In the cleaning step, since the size of the infrared detector chip is not large, the present invention uses a clean dust-free fingertip for scrubbing. Compared with other tools such as dust-free cloth and brush, the contact surface is smoother and no additional scratches are generated.

[0027] 4. The first step of the cleaning process of the present invention is water mist cleaning, using high-speed N 2 Spraying water mist combined with deionized water onto the surface to be cleaned is a more conventional cleaning step that only targets particle contaminants of 1 to 3 μm. This step is indispensable and creates more favorable cleaning conditions for subsequent cleaning of the chip surface to avoid adding new scratches.

[0028] 5. The fourth step of the cleaning step of the present invention is to scrub the surface with an alkaline cleaning agent, which is an important part of the cleaning step. It utilizes that the focal plane substrate material of the type II superlattice infrared detector chip is a III-V group material, and the sodium hypochlorite polishing liquid is used for polishing. The derivatives produced are amphoteric oxides, which can react with the components in the alkaline cleaning agent to generate soluble salt substances. At the same time, the alkaline cleaning agent can make the above-mentioned particle pollution and the surface of the material after polishing negatively charged, so that some pollutants are separated from the substrate surface due to repulsion, thereby ensuring the cleanliness of the polished surface of the chip.

[0029] 6 In the cleaning step, megasonic cleaning is combined with organic solvent cleaning, which is an important part of the cleaning step. The megasonic frequency used in the present invention is 950KHZ and the power is 0.8KW. Compared with ordinary ultrasonic cleaning, the frequency is higher and the removal effect is more significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings:

[0031] Figure 1 This is a cleaning process flow chart of the infrared detector chip after final polishing using the traditional organic cleaning method;

[0032] Figure 2 A flow chart of the cleaning method proposed by the present invention;

[0033] Figure 3 This is a flow chart of the additional steps of the cleaning method proposed by the present invention compared to traditional cleaning;

[0034] Figure 4 A three-dimensional schematic diagram of the cleaning tool proposed by the present invention;

[0035] Figure 5 for Figure 4 A front view of

[0036] Figure 6-7Schematic diagram of using a cleaning tool to place an infrared detector chip with a specification of 640×512 and a pixel center distance of 25um, and an infrared detector chip with a specification of 640×512 and a pixel center distance of 15um;

[0037] Figure 8 for Figure 2 The negative charge mechanism diagram of the alkaline cleaning agent shown;

[0038] Fig. 9 This is a dark field microscope image of the chip surface after traditional organic cleaning;

[0039] Fig.10 A dark field microscope image of the chip surface after cleaning using the method of the present invention;

[0040] In the figure: 1 is the first chip placement platform, 2 is the second chip placement platform, 3 is the third chip placement platform, 4 is the fourth chip placement platform, 5 is the fifth chip placement platform, 6 is the tweezers clamping groove, and 7 is the water flow groove. DETAILED DESCRIPTION

[0041] like Figures 2 to 10 As shown, the present invention provides a cleaning method for improving the cleanliness of the polished surface of a large array infrared detector, and also designs a corresponding cleaning tool for placing infrared detector chips of different sizes to be cleaned to assist in cleaning. The specific cleaning steps are as follows:

[0042] Step S1: Rinse the polished surface of the infrared detector chip with water mist. This cleaning step is performed before the infrared detector chip is removed from the glass substrate after polishing. 2 The high-speed airflow is mixed with deionized water (DI water) and sprayed out through the nozzle to form atomized water droplets at high speed. The flushing time is 20 seconds.

[0043] Step S2: scrub the infrared detector chip with detergent and DI water. After taking the chip, the infrared detector chip is placed in the cleaning tool. The subsequent cleaning steps S3-S5 are all cleaned on the cleaning tool. Specifically:

[0044] First, DI water is used to overflow the surface of the infrared detector chip to achieve a wetting effect. Then, a dust-free clean finger cot is used to dip a detergent (whose ingredients include surfactants, chelating agents, etc.) and mix it with DI water. Use the ring finger to slowly wipe the polished surface in one direction of the infrared detector chip for 2-3 times. This can remove the residual polymer and some Al on the surface of the infrared detector chip after polishing. 2 O 3 Particles.

[0045] Step S3: Rinse the surface of the infrared detector chip with DI water. In this cleaning step, a fixed nozzle is used to spray DI water at a low speed toward the center of the infrared detector chip. The rinsing time is 20 seconds.

[0046] Step S4: Use an alkaline cleaning agent to scrub the surface of the infrared detector chip, wherein the alkaline cleaning agent is: (sodium hydroxide solution with a concentration of less than 5%, sodium carbonate solution with a concentration of less than 5%, sodium hypochlorite solution with a concentration of less than 5%, tetrasodium glutamate diacetate solution with a concentration of less than 5%): DI water = 5ml:100ml. In this cleaning step, first use a dropper to absorb a small amount of the proportioned solution, rinse the surface of the infrared detector chip 2-3 times, then wear a new dust-free clean finger glove, dip it in the proportioned solution, and use the ring finger to slowly wipe the polished surface in one direction of the infrared detector chip, and wipe it 2-3 times.

[0047] Step S5: Use DI water to rinse the surface of the infrared detector chip. In this cleaning step, a fixed nozzle is used to spray DI water at a low speed toward the center of the infrared detector chip. The rinsing time is 20 seconds.

[0048] Step S6: Use an organic solvent combined with megasonic cleaning to clean the surface of the infrared detector chip. In this cleaning step, first take out the above-treated infrared detector chip from the cleaning tool and place it in a polytetrafluoroethylene basket. Place the polytetrafluoroethylene basket in a beaker filled with acetone, place the beaker in a megasonic cleaning tank, and perform megasonic cleaning for 5 minutes at room temperature. Then take out the infrared detector chip and the polytetrafluoroethylene basket and place them in a beaker filled with ethanol. Place them in a megasonic cleaning tank and perform megasonic cleaning for 5 minutes at room temperature. Finally, place the infrared detector chip and the polytetrafluoroethylene basket in a beaker filled with isopropanol, place them in a megasonic cleaning tank, and perform megasonic cleaning at 60°C in a water bath for 3 minutes to remove ethanol residue. In the above process, the megasonic frequency of the megasonic cleaning is 950KHZ and the power is 0.8KW. After cleaning, use N 2 To dry the infrared detector chip, take it out of the hot isopropyl alcohol and blow N 2 Move the isopropyl alcohol to the center of the infrared detector chip and blow it around the infrared detector chip in a rotating motion for 10-15 seconds to prevent the isopropyl alcohol from splashing onto the surface of the infrared detector chip.

[0049] The structure of the cleaning tool is as follows Figure 4-5 As shown in FIG. 1 , the cleaning tool comprises a sample placement table for placing infrared detector chips of various sizes, a tweezer gripping part and a water flow trough part, as shown in FIG. Figure 4As shown, the sample placement table is a groove, and a gap is provided between the groove and the bottom plate of the cleaning tool (that is, the sample placement table is higher than the water flow groove 7). The gap is the water flow groove 7, that is, the water flow groove 7 is under the sample placement table, and the side of the sample placement table is the tweezers clamping groove 6. The infrared detector chip taken out after polishing is placed in the corresponding groove according to the specifications. The sum of the height of the sample placement table and the height of the infrared detector chip after thinning is equal to the height of the adjacent boss. The infrared detector chip can be fixed during the scrubbing process, and the consistent height can ensure the cleanliness of the edges and corners of the infrared detector chip during the cleaning process. The tweezers clamping groove 6 is convenient for placing and taking the chip, and the water flow groove 7 can facilitate the discharge of cleaning waste liquid.

[0050] The sample placement table includes a first chip placement table 1, a second chip placement table 2, a third chip placement table 3, a fourth chip placement table 4 and a fifth chip placement table 5. The first chip placement table 1 can place an infrared detector chip with a specification (i.e., resolution or array size or pixel array) of 1280×1024 and a pixel center distance of 15um. The second chip placement table 2 can place an infrared detector chip with a specification of 640×512 and a pixel center distance of 25um. The third chip placement table 3 can place an infrared detector chip with a specification of 640×512 and a pixel center distance of 15um. The fourth chip placement table 4 can place an infrared detector chip with a specification of 320×256 and a pixel center distance of 30um. The fifth chip placement table 5 can place an infrared detector chip with a specification of 1024×1024 and a pixel center distance of 20um. Figure 6-7 The placement details of an infrared detector chip with a size of 640×512 and a pixel center distance of 25 um, and an infrared detector chip with a size of 640×512 and a pixel center distance of 15 um are shown.

[0051] The principle of the cleaning step of the present invention is further explained below.

[0052] In step S1, the water mist washing (for particle pollutants of 1 to 3 μm) uses high-speed water mist to spray onto the cleaned surface for the lower sheet, which can achieve better cleaning effect with low damage.

[0053] In step S2, the detergent is combined with DI water for scrubbing (for 0.2~1μm particle contaminants), and DI water overflow is used to clean the dust and large particle impurities introduced from the environment and wet the infrared detector chip. Then, the detergent is combined with DI water for scrubbing, and the soft dust-free clean finger gloves are in continuous contact with the surface of the infrared detector chip. Combined with the high lubrication of the detergent and the dragging force of the hydraulic force, the surface is lubricated and the wiping damage is reduced. At the same time, the Al2O3 physically adsorbed on the surface of the infrared detector chip during the polishing process is removed. 2 O 3Solid particles, as they are placed on the cleaning tooling, can fix the infrared detector chip during wiping, and the infrared detector chip is placed on the cleaning tooling at the same height as the cleaning tooling, so that the infrared detector chip will not shift and cause problems such as unclean wiping or uneven force.

[0054] The DI water washing in step S3 is mainly used to clean the residual detergent and the large-sized solid particles wiped off by mechanical friction.

[0055] In step S4, the alkaline cleaning agent is used for wiping (for pollutants with particle size of 0.1-0.2 μm). The pollutants to be treated in this process mainly include residual Al 2 O 3 Particles and process derivatives (Ga 2 O 3 , Sb 2 O 3 , Sb 2 O 5 ) etc., Ga 2 O 3 , Sb 2 O 3 , Sb 2 O 5 All of them are amphoteric oxides and can react chemically with the alkaline components in alkaline cleaning agents to generate soluble antimonites, antimonates and gallates. The chemical reaction formula is as follows:

[0056] ;

[0057] ;

[0058] .

[0059] At the same time, the alkaline cleaning agent can make the above-mentioned particle pollution and the surface of the polished material negatively charged, so that some pollutants are separated from the substrate surface of the infrared detector chip due to repulsion. The principle diagram is as follows Figure 8 As shown, by using a straw to absorb the alkaline cleaning agent for multiple rinses, and then wiping with a dust-free finger cot dipped in the alkaline cleaning agent, small-sized particles and process derivatives can be wiped off, and the pollutants can be completely removed through subsequent DI water rinsing.

[0060] The DI water rinse in step S5 is mainly used to clean the residual alkaline cleaning agent, the small-sized particles wiped off, and the process derivatives.

[0061] Step S6 is organic cleaning + megasonic cleaning (for particle pollutants <0.1μm). Organic cleaning uses the principle of chemical similarity to dissolve the metal PAD protective glue in acetone solution. This step can remove the protective glue of the metal PAD of the protective chip and the protective glue adhering to the polished surface during polishing. Then, ethanol is used to dissolve the acetone remaining on the surface of the infrared detector chip. Finally, isopropanol is used to remove the ethanol residue. Heating isopropanol during organic cleaning helps the detector surface to dry quickly. Megasonic cleaning uses physical cleaning methods such as vibration to allow surface pollutants to gain energy and separate from the surface of the material. Megasonic cleaning reduces the contamination caused by the cleaning itself and causes less damage to the surface. The cleaning effect is better when organic cleaning is combined with megasonic cleaning. Finally, after cleaning is completed, the infrared detector chip is taken out of the hot isopropanol solution and passed through N 2 Use a cleaning gun to quickly blow off the residual isopropyl alcohol on the surface of the infrared detector chip to obtain a clean infrared detector chip.

[0062] The cleaning method provided by the present invention can firstly wash away the large-sized solid particles and dust and other pollutants remaining after the polishing of the InAs / GaSbⅡ type superlattice infrared detector chip by water mist. In the subsequent detergent and DI water wiping, combined with the designed cleaning tooling, the infrared detector chip will not move during the scrubbing process to cause problems such as uneven wiping force and inadequate wiping. The detergent has a high lubricating effect and will not cause scratches on the detector surface. It can also remove smaller-sized solid particles. In the next step, the DI water rinse cleans the pollutants wiped by the detergent together with the detergent. Therefore, when performing the subsequent alkaline cleaning process, derivatives that cannot be removed and adhere to the infrared detector chip will not be generated. In the alkaline cleaning agent step, the polishing liquid residue and process derivatives are further reduced. Then, the residual alkaline cleaning agent is removed by DI water rinsing. Finally, the organic matter remaining on the surface of the infrared detector chip and the protective glue protecting the metal PAD of the chip and the small-sized solid particles on the chip surface are cleaned by organic cleaning and megasonic cleaning, and N 2 Gun blow dry.

[0063] The traditional final post-polishing cleaning process can only remove 1~3um particles using water mist cleaning, and the subsequent organic cleaning only removes the protective glue on the metal PAD, leaving a large amount of polishing liquid residue and derivatives on the surface. Fig. 9 This is a dark field microscope image of the chip surface after traditional organic cleaning. The cleaning tool designed according to the present invention combined with the corresponding cleaning method can not only remove impurities such as polishing liquid residues and process derivatives below 0.1um to obtain a clean surface, but also improve the particle performance after the final polishing cleaning. Fig.10 This is a dark field microscope image of the chip surface after being cleaned by the method of the present invention.

[0064] The cleaning tool in the present invention is also applicable to the surface cleaning of chips of the above specifications after grinding and polishing; the cleaning steps of the present invention are also applicable to the surface cleaning method of type II superlattice infrared detector chips of group III-V materials after grinding and polishing, such as InP, GaSb, InAsSb and other materials.

[0065] Finally, 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cleaning method for improving the cleanliness of the polished surface of a large array infrared detector, characterized in that: The following steps are involved: Step S1: for particle pollutants of 1 to 3 μm, the polished surface of the infrared detector chip is washed by water mist before the infrared detector chip is taken out after polishing; Step S2: For the particle pollutants of 0.2~1μm, after taking the chip, the infrared detector chip is placed in the cleaning tool, and the infrared detector chip is scrubbed with detergent and DI water. The subsequent cleaning steps S3-S5 are all cleaned on the cleaning tool; Step S3: Rinse the surface of the infrared detector chip with DI water; Step S4: For pollutants with a particle size of 0.1-0.2 μm, use an alkaline cleaning agent to scrub the surface of the infrared detector chip; the alkaline cleaning agent in step S4 is: (sodium hydroxide solution with a concentration of less than 5%, sodium carbonate solution with a concentration of less than 5%, sodium hypochlorite solution with a concentration of less than 5%, tetrasodium glutamate diacetate solution with a concentration of less than 5%): DI water = 5 ml: 100 ml of the ratio solution; In step S4, first use a dropper to absorb a small amount of the proportioned solution, rinse the surface of the infrared detector chip 2-3 times, then wear a new dust-free clean finger glove, dip it in the proportioned solution, and slowly wipe the polished surface in one direction of the infrared detector chip, wiping 2-3 times; Step S5: Rinse the surface of the infrared detector chip with DI water; Step S6: For particulate pollutants <0.1μm, the surface of the infrared detector chip is cleaned by combining organic solvent and megasonic cleaning; before cleaning in step S6, the infrared detector chip is first removed from the cleaning tool, and then the infrared detector chip is sequentially subjected to acetone megasonic cleaning, ethanol megasonic cleaning and isopropyl alcohol megasonic cleaning, and finally blown dry with N2.

2. A cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to claim 1, characterized in that: The cleaning tooling includes a sample placement table that can hold infrared detector chips of various sizes, a tweezers clamping part and a water flow trough part. The sample placement table is a groove with a water flow trough between the groove and the bottom plate of the cleaning tooling. The side of the sample placement table is a tweezers clamping groove. The infrared detector chips taken after polishing are placed in the corresponding grooves according to specifications.

3. A cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to claim 2, characterized in that: The sum of the height of the sample placement table and the height of the infrared detector chip after thinning is equal to the height of the boss on one side of the groove.

4. The cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to claim 1, characterized in that: Step S2 specifically includes: First, DI water is overflowed onto the surface of the infrared detector chip to achieve a wetting effect; Then use a dust-free clean finger cot, dip it in a mixture of detergent and DI water, and slowly wipe the polished surface in one direction of the infrared detector chip. Repeat the wipe 2-3 times.

5. The cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to claim 1, characterized in that: In steps S3 and S5, the DI water is used to rinse the surface of the infrared detector chip by spraying the DI water at a low speed toward the center of the infrared detector chip by a fixed nozzle.

6. The cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to claim 2, characterized in that: The sample placement table includes a first chip placement table, a second chip placement table, a third chip placement table, a fourth chip placement table and a fifth chip placement table. The first chip placement table is used to place an infrared detector chip with a specification of 1280×1024 and a pixel center distance of 15um. The second chip placement table is used to place an infrared detector chip with a specification of 640×512 and a pixel center distance of 25um. The third chip placement table is used to place an infrared detector chip with a specification of 640×512 and a pixel center distance of 15um. The fourth chip placement table is used to place an infrared detector chip with a specification of 320×256 and a pixel center distance of 30um. The fifth chip placement table is used to place an infrared detector chip with a specification of 1024×1024 and a pixel center distance of 20um.

7. A cleaning method for improving the cleanliness of the polished surface of a large-array infrared detector according to any one of claims 1 to 6, characterized in that: The infrared detector chip is a type II superlattice infrared detector chip using III-V group materials.

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