A method for stress conditioning of passivation film in infrared detectors
By preparing a transition film between the silicon oxide and silicon nitride stacked passivation films of a III-V infrared detector and treating it with oxygen and nitrogen plasma, the warping and reliability problems caused by high stress in the passivation film were solved, thus improving the performance and reliability of the device.
Patent Information
- Application Number
- CN202310987145.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2023-05-11
- Filing Date
- 2023-08-07
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2043-08-07
AI Technical Summary
In the existing technology, the silicon oxide and silicon nitride stacked passivation film of III-V infrared detectors suffers from high stress during the fabrication process, which leads to large warpage, degraded device performance, and reduced reliability. In particular, when connecting the chip to the readout circuit, it is easy to cause problems such as reduced connectivity and low yield.
A transition film layer is prepared between silicon oxide and silicon nitride stacked passivation films. The stress inside the film is adjusted by oxygen plasma and nitrogen plasma treatment, the atomic defects in the film are filled, and the stress concentration is reduced.
It effectively adjusts the warpage of the passivation film, improves device reliability and yield, reduces the risk of chip failure, ensures that the passivation film does not fall off under high and low temperature shocks, and has good adhesion.
Smart Images
Figure CN117248198B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a stress adjustment method for a passivation film of a III-V group infrared detector, belonging to the field of infrared detector technology. Background Technology
[0002] Most short-wave infrared detectors, such as lead sulfide (PbS) and indium arsenide (InAs), have complex fabrication methods and require operating temperatures below liquid nitrogen. This makes them cost-inefficient and hinders the development of short-wave infrared detection systems towards miniaturization, lightweight design, and ease of use. Indium gallium arsenide (InAs), a III-V ternary compound material,... x Ga 1-x Indium gallium arsenide (GaAs) has a direct bandgap structure, and its bandgap width is adjustable from 0.35 eV to 1.43 eV as x changes, covering the short-wave infrared band (1 μm to 3 μm). Moreover, the Indium Gallium Arsenide (GaAs) infrared detection system can operate near room temperature and exhibits high detectivity and high quantum efficiency, making Indium Gallium Arsenide (GaAs) infrared detectors increasingly widely used in military and civilian fields, such as handheld low-light night vision devices, biomedicine, and environmental monitoring.
[0003] As application requirements become increasingly stringent, focal plane arrays in indium gallium arsenide (IGaAs) infrared detectors are evolving towards larger array sizes, smaller pixels, and higher sensitivity. Array devices have already progressed from small-scale to medium- and large-scale (640×512 pixels). For 1024×1024 pixels and larger array devices, high-performance IGaAs infrared detectors need to be developed. A crucial factor affecting the performance of large-scale array devices in focal plane array detectors is the passivation film. Therefore, the requirements for the flatness and reliability of the passivation film used in focal plane detectors are becoming increasingly stringent. Especially during the flip-flop bonding process between the chip and the readout circuit, a large flatness error can cause chip warping, directly leading to reduced connectivity between the chip and the readout circuit, resulting in poor chip performance and low yield.
[0004] Currently, most passivation films for focal plane array detectors, such as silicon oxide, silicon nitride, or silicon oxide / silicon nitride stacked passivation films, are grown using inductively coupled plasma chemical vapor deposition (ICP-CVD). This method uses alternating current to inductively couple magnetic and electric fields to generate plasma for fabrication. This deposition method offers advantages such as relatively minimal damage to the sample and good film uniformity and coverage. However, ICP-CVD suffers from high stress in the grown film, leading to significant surface warpage, decreased device performance, and reduced reliability. Furthermore, high-stress passivation films are prone to detachment and cracking. Therefore, adjusting the stress of the passivation film is crucial to addressing these issues.
[0005] To address the issue of high stress in passivation films grown by inductively coupled plasma chemical vapor deposition (ICP-CVD), existing technologies can achieve this by optimizing process parameters, including process gas flow rate, gas pressure, and power. However, there are currently no reports on resolving the stress problem in the fabrication of silicon oxide and silicon nitride stacked passivation films for III-V group infrared focal plane detectors by preparing a transition film layer. Summary of the Invention
[0006] To overcome the shortcomings of existing technologies, the present invention aims to provide a stress adjustment method for the passivation film of an infrared detector. This method, through the preparation of a transition film layer, solves the stress problem existing in the preparation of silicon oxide and silicon nitride stacked passivation films for III-V group infrared focal plane detectors. It is particularly suitable for solving the stress problem existing in the preparation of silicon oxide and silicon nitride stacked passivation films for indium gallium arsenide infrared detectors. This method can adjust the warpage of the passivation film layer, improve device reliability, and reduce the risk of chip failure.
[0007] To achieve the objectives of this invention, the following technical solutions are provided.
[0008] A method for stress conditioning an infrared detector passivation film, wherein the infrared detector is a III-V group infrared focal plane detector, preferably an indium gallium arsenide focal plane detector; the passivation film is a silicon oxide and silicon nitride stacked passivation film; the method is inductively coupled plasma chemical vapor deposition, and the steps are as follows:
[0009] (1) Preparation of silicon oxide film
[0010] After cleaning the chamber of the inductively coupled plasma chemical vapor deposition (ICP-CVD) equipment, a substrate used for the focal plane detector is placed in it. A silicon oxide film with a thickness of 100 nm to 140 nm is prepared on the substrate using conventional techniques for depositing silicon oxide films using the ICP-CVD equipment in this field.
[0011] The preferred preparation method for step (1) is as follows:
[0012] Maintain the temperature of the outer wall of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of process gas A introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The RF power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film with a thickness of 100nm to 140nm is prepared on the substrate.
[0013] The process gas A is oxygen (O2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0014] In step (1), before depositing the silicon oxide film, the chamber of the inductively coupled plasma chemical vapor deposition (ICP-CVD) equipment is cleaned. This cleaning can be performed using conventional techniques employed in the field for depositing passivation films using ICP-CVD equipment; plasma cleaning is preferred. The specific cleaning method is as follows:
[0015] ① Evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 For pressures below Pa, the outer wall temperature of the chamber should be set to 40℃~60℃;
[0016] ② Introduce gases O2, CF4 and Ar into the chamber until the pressure reaches 1 Pa to 3 Pa, turn on the radio frequency power supply, set the power to 600 W to 900 W, and run continuously for 20 min to 40 min.
[0017] ③ Turn off the radio frequency power supply, stop the gas supply, and end the chamber cleaning.
[0018] (2) Preparation of transition film layer
[0019] After the silicon oxide film is prepared, maintain the temperature of the outer wall of the chamber at 40℃~60℃, and evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 Below Pa, process gas B is introduced into the chamber at a pressure of 4 Pa to 6 Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 180 W to 240 W. No heating is performed during the process to deposit the transition film layer for 5 min to 10 min. The pressure is stable throughout the deposition process, and the transition film layer is prepared on the silicon oxide film layer.
[0020] The process gas B is oxygen (O2) and nitrogen (N2).
[0021] (3) Preparation of silicon nitride film
[0022] After the transition film is prepared, a silicon nitride film with a thickness of 200 nm to 260 nm is prepared on the transition film using conventional techniques for depositing silicon nitride films using inductively coupled plasma chemical vapor deposition equipment in this field.
[0023] The preferred preparation method for step (3) is as follows:
[0024] Maintain the temperature of the outer wall of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of the process gas C introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit the silicon nitride film. The pressure is stable throughout the deposition process, and a silicon nitride film with a thickness of 200nm to 260nm is prepared.
[0025] The process gas C is nitrogen (N2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0026] Beneficial effects
[0027] (1) The present invention provides a stress adjustment method for the passivation film of an infrared detector. The method prepares a transition film layer between a silicon oxide film and a silicon nitride film by plasma treatment with an oxygen source and a nitrogen source atmosphere. During the deposition of the silicon oxide film, there will be atomic (e.g., oxygen atom) vacancies in the film, forming defects in the film, causing lattice distortion, and causing stress concentration in the passivation film. The oxygen plasma can diffuse on the deposited silicon oxide film and fill some of the missing oxygen atoms, thus releasing the stress of the film. The nitrogen source plasma can adhere to the silicon oxide film and fill some of the missing nitrogen atoms in the silicon nitride film when the silicon nitride film is deposited, thereby achieving the stress adjustment of the silicon oxide and silicon nitride stacked passivation film.
[0028] (2) The present invention provides a stress adjustment method for the passivation film of an infrared detector. The method only requires the preparation of a transition layer between a silicon oxide film and a silicon nitride film to achieve the effect. The deposition method of the silicon oxide film and the silicon nitride film is still the existing technology method, which is convenient for production implementation.
[0029] (3) The present invention provides a stress adjustment method for an infrared detector passivation film. The method is applicable to stress adjustment between a silicon oxide film layer with a thickness of 100nm to 140nm and a silicon nitride film layer with a thickness of 200nm to 260nm. The above technique can effectively affect the stress value of the passivation film within the passivation film thickness range. If the passivation film thickness is not within this range, the stress adjustment may not be obvious.
[0030] (4) The present invention provides a stress adjustment method for the passivation film of an infrared detector. The degree of warpage of the passivation film prepared by the method is adjusted, that is, the stress value of the film layer changes. This conclusion can be seen in the following embodiments. The passivation film prepared by the present invention has high reliability. The passivation film system does not fall off after high and low temperature shocks and has good adhesion to the material. This conclusion can be seen in the following embodiments, which improves the reliability of the device in practical applications. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the passivation film structure prepared by the stress adjustment method of the infrared detector passivation film according to the present invention.
[0032] Wherein, 1—substrate, 2—silicon oxide film, 3—transition film, 4—silicon nitride film. Detailed Implementation
[0033] To facilitate a further understanding of the technical solutions of the present invention, some preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings and specific examples, but these are not intended to limit the scope of the present invention.
[0034] Example 1
[0035] A method for stress adjustment of the passivation film of an infrared detector, the method comprising the following steps:
[0036] (1) The chamber of the inductively coupled plasma chemical vapor deposition equipment is cleaned using plasma cleaning. The specific cleaning method is as follows:
[0037] ① Evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 For pressures below Pa, set the outer wall temperature of the chamber to 40℃.
[0038] ② Introduce gases O2, CF4 and Ar into the chamber until the pressure reaches 1 Pa, turn on the radio frequency power supply, set the power to 900W, and run continuously for 20 minutes.
[0039] ③ Turn off the radio frequency power supply, stop the gas supply, and end the chamber cleaning.
[0040] (2) Preparation of silicon oxide film
[0041] After cleaning, the substrate used in the indium gallium arsenide focal plane detector, namely an indium gallium arsenide material sheet, is placed into the chamber. The outer wall temperature of the chamber is maintained at 40°C, and the chamber's base vacuum is evacuated to 1×10⁻⁶. -4 Below Pa, process gas A is introduced into the chamber at a pressure of 10 Pa and the pressure is stable. The radio frequency power supply is turned on at a power of 180 W and the deposition temperature is 80 °C to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film with a thickness of 100 nm is prepared on the substrate.
[0042] The process gas A is oxygen (O2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0043] (3) Preparation of transition film layer
[0044] After the silicon oxide film is prepared, maintain the outer wall temperature of the chamber at 40°C and evacuate the chamber to a background vacuum of 1×10⁻⁶. - 4 Below Pa, process gas B is introduced into the chamber at a pressure of 4 Pa and the pressure is stable. The radio frequency power supply is turned on at a power of 200W and deposition is carried out continuously for 5 minutes. The pressure is stable throughout the deposition process, and a transition film is prepared on the silicon oxide film.
[0045] The process gas B is oxygen (O2) and nitrogen (N2).
[0046] (4) Preparation of silicon nitride film
[0047] After the transition film layer is prepared, maintain the outer wall temperature of the chamber at 40℃ and evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 Below Pa, process gas C was introduced into the chamber to a pressure of 10 Pa and the pressure was stable. The radio frequency power supply was turned on with a power of 180 W and the deposition temperature was 80 °C to deposit a silicon nitride film. The pressure was stable throughout the deposition process, and a silicon nitride film with a thickness of 260 nm was prepared.
[0048] The process gas C is nitrogen (N2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0049] The passivation film structure prepared in this embodiment is as follows: Figure 1 As shown, from bottom to top, the layers are: substrate 1, silicon oxide film 2, transition film 3, and silicon nitride film 4.
[0050] The passivation film prepared in this embodiment was subjected to the following tests:
[0051] (1) Membrane stress test
[0052] The test was conducted in a clean room at a temperature of 18°C to 23°C and a relative humidity of 40% to 60%. The test instrument used was a KLA-P7. The stress value of the passivation film layer prepared in this embodiment was 51.69 MPa.
[0053] To compare with the stress test of the passivation film prepared in Example 1, the passivation film was prepared using the same parameters as in steps (1) and (3) of Example 1, but without step (2) as Comparative Example 1. The passivation film obtained was subjected to the same stress test method, and the stress value was 198.8 MPa.
[0054] The stress curves obtained in Example 1 and Comparative Example 1 during stress testing differ significantly. A comparison of the stress test results clearly demonstrates that the passivation film preparation method described in this patent application can effectively adjust the film stress.
[0055] (2) Reliability Testing
[0056] The test method is as follows: A temperature shock test was conducted on the passivation film. The passivation film was subjected to a high temperature of ≥85℃ to room temperature, and then from room temperature to liquid nitrogen temperature. This process was repeated three times, with each temperature point held for ≥10 minutes. After the temperature shock test, the results showed that the passivation film remained intact, without any damage or cracking. Next, a 2cm wide adhesive tape was applied to the surface of the passivation film, and a tensile tester was used to pull it vertically. The peel strength was >2.7 N / cm, and no film detachment occurred, indicating that the passivation film has excellent adhesion.
[0057] Example 2
[0058] A method for stress adjustment of the passivation film of an infrared detector, the method comprising the following steps:
[0059] (1) The chamber of the inductively coupled plasma chemical vapor deposition equipment is cleaned using plasma cleaning. The specific cleaning method is as follows:
[0060] ① Evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 For pressures below Pa, set the outer wall temperature of the chamber to 40℃.
[0061] ② Introduce gases O2, CF4 and Ar into the chamber until the pressure reaches 3 Pa, turn on the radio frequency power supply, set the power to 600W, and run continuously for 40 minutes.
[0062] ③ Turn off the radio frequency power supply, stop the gas supply, and end the chamber cleaning.
[0063] (2) Preparation of silicon oxide film
[0064] After cleaning, the substrate used in the indium gallium arsenide focal plane detector, namely an indium gallium arsenide material sheet, is placed into the chamber. The outer wall temperature of the chamber is maintained at 40°C, and the chamber's base vacuum is evacuated to 1×10⁻⁶. -4 Below Pa, process gas A is introduced into the chamber at a pressure of 7 Pa and the pressure is stable. The radio frequency power supply is turned on at a power of 160 W and the deposition temperature is 80 °C to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film with a thickness of 110 nm is prepared on the substrate.
[0065] The process gas A is oxygen (O2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0066] (3) Preparation of transition film layer
[0067] After the silicon oxide film is prepared, maintain the outer wall temperature of the chamber at 40°C and evacuate the chamber to a background vacuum of 1×10⁻⁶. - 4Below Pa, the pressure of process gas B introduced into the chamber is 4 Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 180W and the deposition is carried out continuously for 10 minutes. The pressure is stable throughout the deposition process, and a transition film is prepared on the silicon oxide film.
[0068] The process gas B is oxygen (O2) and nitrogen (N2).
[0069] (4) Preparation of silicon nitride film
[0070] After the transition film layer is prepared, maintain the outer wall temperature of the chamber at 40℃ and evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 Below Pa, process gas C was introduced into the chamber to a pressure of 7 Pa and the pressure was stable. The radio frequency power supply was turned on with a power of 160 W and a deposition temperature of 80 °C to deposit a silicon nitride film. The pressure remained stable throughout the deposition process, and a silicon nitride film with a thickness of 250 nm was prepared.
[0071] The process gas C is nitrogen (N2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0072] The passivation film structure prepared in this embodiment is as follows: Figure 1 As shown, from bottom to top, the layers are: substrate 1, silicon oxide film 2, transition film 3, and silicon nitride film 4.
[0073] The passivation film prepared in this embodiment was subjected to the following tests:
[0074] (1) Membrane stress test
[0075] The test was conducted in a clean room at a temperature of 18°C to 23°C and a relative humidity of 40% to 60%. The test instrument used was a KLA-P7. The stress value of the passivation film layer prepared in this embodiment was 106.0 MPa.
[0076] To compare with the stress test of the passivation film prepared in Example 2, the passivation film was prepared using the same parameters as steps (1) and (3) in Example 2, but without step (2) as Comparative Example 2. The passivation film obtained was subjected to the same stress test method, and the stress value was 347.7 MPa.
[0077] The stress curves obtained in Example 2 and Comparative Example 2 during stress testing differ significantly. A comparison of the stress test results clearly demonstrates that the passivation film preparation method described in this patent application can effectively adjust the film stress.
[0078] (2) Reliability Testing
[0079] The test method is as follows: A temperature shock test was conducted on the passivation film. The passivation film was subjected to a high temperature of ≥85℃ to room temperature, and then from room temperature to liquid nitrogen temperature. This process was repeated three times, with each temperature point held for ≥10 minutes. After the temperature shock test, the results showed that the passivation film remained intact, without any damage or cracking. Next, a 2cm wide adhesive tape was applied to the surface of the passivation film, and a tensile tester was used to pull it vertically. The peel strength was >2.7 N / cm, and no film detachment occurred, indicating that the passivation film has excellent adhesion.
[0080] Example 3
[0081] A method for stress adjustment of the passivation film of an infrared detector, the method comprising the following steps:
[0082] (1) The chamber of the inductively coupled plasma chemical vapor deposition equipment is cleaned using plasma cleaning. The specific cleaning method is as follows:
[0083] ① Evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 For pressures below Pa, set the temperature of the outer wall of the chamber to 60℃.
[0084] ② Introduce gases O2, CF4 and Ar into the chamber until the pressure reaches 3 Pa, turn on the radio frequency power supply, set the power to 800W, and run continuously for 30 minutes.
[0085] ③ Turn off the radio frequency power supply, stop the gas supply, and end the chamber cleaning.
[0086] (2) Preparation of silicon oxide film
[0087] After cleaning, the substrate used in the indium gallium arsenide focal plane detector, namely an indium gallium arsenide material sheet, is placed into the chamber. The outer wall temperature of the chamber is maintained at 60°C, and the chamber's base vacuum is evacuated to 1×10⁻⁶. -4 Below Pa, process gas A is introduced into the chamber at a pressure of 12 Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 210 W and the deposition temperature is 80 °C to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film with a thickness of 140 nm is prepared on the substrate.
[0088] The process gas A is oxygen (O2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0089] (3) Preparation of transition film layer
[0090] After the silicon oxide film is prepared, maintain the outer wall temperature of the chamber at 60°C and evacuate the chamber to a background vacuum of 1×10⁻⁶. - 4Below Pa, the pressure of process gas B introduced into the chamber is 6 Pa and the pressure is stable. The RF power supply is turned on with a power of 240W and the deposition is carried out for 7 minutes. The pressure is stable throughout the deposition process, and a transition film is prepared on the silicon oxide film.
[0091] The process gas B is oxygen (O2) and nitrogen (N2).
[0092] (4) Preparation of silicon nitride film
[0093] After completing the above steps, evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 Below Pa, process gas C was introduced into the chamber to a pressure of 12 Pa and the pressure was stable. The radio frequency power supply was turned on with a power of 210 W and the deposition temperature was 80 °C to deposit a silicon nitride film. The pressure remained stable throughout the deposition process, and a silicon nitride film with a thickness of 200 nm was prepared.
[0094] The process gas C is nitrogen (N2), argon (Ar) and helium (He) containing 5% silane (SiH4) by volume.
[0095] The passivation film structure prepared in this embodiment is as follows: Figure 1 As shown, from bottom to top, the layers are: substrate 1, silicon oxide film 2, transition film 3, and silicon nitride film 4.
[0096] The passivation film prepared in this embodiment was subjected to the following tests:
[0097] (1) Membrane stress test
[0098] The test was conducted in a clean room at a temperature of 18°C to 23°C and a relative humidity of 40% to 60%. The test instrument used was a KLA-P7. The stress value of the passivation film layer prepared in this embodiment was 86.47 MPa.
[0099] To compare with the stress test of the passivation film prepared in Example 3, the passivation film was prepared using the same parameters as steps (1) and (3) in Example 3, but without step (2) as Comparative Example 3. The passivation film obtained was subjected to the same stress test method, and the stress value was 192.1 MPa.
[0100] The stress curves obtained in Example 3 and Comparative Example 3 during stress testing differed significantly. A comparison of the stress test results clearly demonstrates that the passivation film preparation method described in this patent application can effectively adjust the film stress.
[0101] (2) Reliability Testing
[0102] The test method is as follows: A temperature shock test was conducted on the passivation film. The passivation film was subjected to a high temperature of ≥85℃ to room temperature, and then from room temperature to liquid nitrogen temperature. This process was repeated three times, with each temperature point held for ≥10 minutes. After the temperature shock test, the results showed that the passivation film remained intact, without any damage or cracking. Next, a 2cm wide adhesive tape was applied to the surface of the passivation film, and a tensile tester was used to pull it vertically. The peel strength was >2.7 N / cm, and no film detachment occurred, indicating that the passivation film has excellent adhesion.
Claims
1. A method for stress adjustment of an infrared detector passivation film, characterized in that: The infrared detector is an indium gallium arsenide focal plane detector, and the passivation film is a silicon oxide and silicon nitride stacked passivation film. The steps are as follows: (1) In the cleaned chamber of the inductively coupled plasma chemical vapor deposition equipment, the substrate used for the focal plane detector is placed, and a silicon oxide film with a thickness of 100 nm to 140 nm is prepared on the substrate by inductively coupled plasma chemical vapor deposition. (2) Maintain the temperature of the outer wall of the chamber at 40℃~60℃, and evacuate the chamber floor vacuum to 1×10 -4 Below Pa, process gas B is introduced into the chamber at a pressure of 4 Pa to 6 Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 180 W to 240 W. No heating is performed during the process to deposit the transition film layer for 5 min to 10 min. The pressure is stable throughout the deposition process, and the transition film layer is prepared on the silicon oxide film layer. The process gas B is oxygen and nitrogen. (3) A silicon nitride film with a thickness of 200 nm to 260 nm was prepared on the transition film by inductively coupled plasma chemical vapor deposition.
2. The stress adjustment method for an infrared detector passivation film according to claim 1, characterized in that: The preparation method for step (1) is as follows: Maintain the outer wall temperature of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of process gas A introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film is prepared on the substrate. The process gas A is oxygen, argon, and helium containing 5% silane by volume.
3. The stress adjustment method for an infrared detector passivation film according to claim 1, characterized in that: The preparation method for step (3) is as follows: Maintain the temperature of the outer wall of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of the process gas C introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit the silicon nitride film. The pressure is stable throughout the deposition process, and the silicon nitride film is prepared on the transition film layer. The process gas C is nitrogen, argon, and helium containing 5% silane by volume.
4. The stress adjustment method for an infrared detector passivation film according to claim 1, characterized in that: The preparation method for step (1) is as follows: Maintain the outer wall temperature of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of process gas A introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit a silicon oxide film. The pressure is stable throughout the deposition process, and a silicon oxide film is prepared on the substrate. The process gas A is oxygen, argon, and helium containing 5% silane by volume; The preparation method for step (3) is as follows: Maintain the outer wall temperature of the chamber at 40℃~60℃, and evacuate the chamber's background vacuum to 1×10⁻⁶. -4 Below Pa, the pressure of the process gas C introduced into the chamber is 7Pa to 12Pa and the pressure is stable. The radio frequency power supply is turned on with a power of 160W to 210W and the deposition temperature is 60℃ to 80℃ to deposit the silicon nitride film. The pressure is stable throughout the deposition process, and the silicon nitride film is prepared on the transition film layer. The process gas C is nitrogen, argon, and helium containing 5% silane by volume.
5. A method for stress adjustment of an infrared detector passivation film according to any one of claims 1 to 4, characterized in that: In step (1), the chamber of the inductively coupled plasma chemical vapor deposition equipment is cleaned before the silicon oxide film is deposited. The cleaning is plasma cleaning.
6. The stress adjustment method for an infrared detector passivation film according to claim 5, characterized in that: The plasma cleaning method is as follows: ① Evacuate the chamber to a background vacuum of 1×10⁻⁶. -4 For pressures below Pa, the outer wall temperature of the chamber should be set to 40℃~60℃; ② Introduce gases O2, CF4 and Ar into the chamber until the pressure is 1Pa to 3Pa, turn on the radio frequency power supply, set the power to 600W to 900W, and run continuously for 20min to 40min; ③ Turn off the radio frequency power supply, stop the gas supply, and end the chamber cleaning.