Method for etching vanadium oxide through DPS metal etching cavity
By controlling the wire length and etching parameters on the DPS Metal Centura 5200 machine, the problem of poor etching rate and surface roughness of vanadium oxide film is solved, and efficient vanadium oxide film etching is achieved, satisfying thermal imaging The performance improvement of the detector and the lithographic morphology requirements.
Patent Information
- Application Number
- CN202411291663.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2025-01-03
AI Technical Summary
In the manufacturing of thermal imaging detectors, it is difficult for the prior art to achieve a high level of uniformity and surface roughness when etching vanadium oxide film layer on DPS metal etching cavity, while the morphology of the side wall after etching does not match the morphology of the etched side wall. The process requirements make it difficult to meet the lithography morphology requirements of the upstream lithography process.
Using the metal etching cavity of the DPS Metal Centura 5200 machine from Applied Materials, the connection between the source RF power supply and the inductor coil is combined with specific etching gases and process parameters such as Cl2 and Ar gases. The flow rate, chamber pressure and RF power supply power control the etching rate and surface roughness of the vanadium oxide film layer to ensure that the inclination angle of the side wall after etching is less than the length of the wire.
The etching rate uniformity and surface roughness of the vanadium oxide film layer are achieved to reach a high level, the side wall morphology meets the process requirements, reduces the lithography morphology requirements of the upstream lithography process, and improves the performance of the thermal imaging detector.
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Figure CN119240597A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductors, and more specifically to a method for etching vanadium oxide in a DPS metal etching chamber. Background Art
[0002] Vanadium oxide bolometer based on MEMS technology is a new type of thermal imaging technology. Its working principle mainly involves preparing vanadium oxide thin films on silicon nitride and silicon oxide substrates, and testing the thermal sensitivity of these films. Studies have shown that vanadium oxide thin films prepared on silicon nitride substrates have better infrared detection performance. Compared with traditional thermal imaging technology, vanadium oxide MEMS technology has the advantages of fast response speed, high resolution, small size and low power consumption.
[0003] Thermal imaging is a technical method to characterize objects based on the infrared radiation characteristics of the object surface. The infrared radiation intensity of the object surface is closely related to the temperature of the object surface. According to Planck's law, the radiation intensity of the object surface is proportional to the fourth power of the surface temperature. Therefore, by measuring the infrared radiation intensity of the object surface, the temperature information of the object surface can be indirectly obtained.
[0004] Thermal imaging technology is a non-contact, non-destructive detection method that can comprehensively characterize the target object. At the same time, its fast measurement speed and high resolution make thermal imaging technology widely used in industry, medicine, environmental protection and other fields. Vanadium oxide is a material with good infrared radiation sensitivity. When vanadium oxide is excited, it will emit a certain infrared radiation signal. Therefore, vanadium oxide can be used as an infrared sensitive element to manufacture thermal imaging detectors.
[0005] In the manufacture of thermal imaging detectors, vanadium oxide needs to be etched, for example, using the metal etching chamber of the DPS MetalCentura 5200 machine from Applied Materials. In order to improve the performance of thermal imaging detectors, it is necessary to further improve the quality of vanadium oxide etching in the DPS metal etching chamber. Summary of the invention
[0006] In view of the problems existing in the background technology, an object of the present disclosure is to provide a method for etching vanadium oxide in a DPS metal etching chamber, which can achieve high levels of uniformity of etching rate and surface roughness of the vanadium oxide film layer and high average etching rate.
[0007] Another object of the present disclosure is to provide a method for etching vanadium oxide in a DPS metal etching chamber, which can make the morphology of the side wall after etching meet the process requirements and the inclination angle of the side wall after etching is smaller than when the length of the wire is short, so as to help reduce the lithography morphology requirements of the upstream lithography process.
[0008] Thus, a method for etching vanadium oxide in a DPS metal etching chamber is provided, wherein the DPS metal etching chamber is a metal etching chamber of a DPS Metal Centura 5200 machine of Applied Materials, Inc., USA. The metal etching chamber of the Centura5200 machine has a source RF power supply and a bias RF power supply, the source RF power supply is connected to the inductor coil through a wire, and the bias RF power supply is electrically connected to the electrostatic chuck in the chamber of the metal etching chamber; the thermal imaging device to be etched is fixed on the electrostatic chuck, in the thermal imaging device to be etched, the vanadium oxide film layer has been plated on the silicon nitride layer and will be etched, and the thickness of the grown vanadium oxide film layer is controlled to be in the range of 68.5-77.9nm; wherein, the length of the wire is controlled to be greater than 15cm but less than 18cm; when etching the vanadium oxide film layer, the pressure of the chamber is 8-12mT, the source power of the source RF power supply is 400-600W, the bias power of the bias RF power supply is 120-200W, the etching gases introduced into the chamber are Cl2 and Ar, the flow rate of Cl2 is 30-60sccm, the flow rate of Ar is 15-25sccm, the etching time is 15-60s, and the etching rate of the vanadium oxide film layer is The uniformity of the etching rate reaches 6-6.5%, and the surface roughness after etching reaches 0.4-1.0 nm.
[0009] The beneficial effects of the present disclosure are as follows.
[0010] In the method of etching vanadium oxide in a DPS metal etching chamber disclosed in the present invention, by controlling the length of the wire between the source RF power supply and the inductor coil of the metal etching chamber of the DPS Metal Centura5200 machine and coordinating the process parameter control for etching the vanadium oxide film layer, the uniformity of the etching rate and the surface roughness of the vanadium oxide film layer can simultaneously reach a high level and the average etching rate can be high.
[0011] In the method of etching vanadium oxide in the DPS metal etching chamber disclosed in the present invention, the morphology of the side wall after etching meets the process requirements, and the inclination angle of the side wall after etching is smaller than that when the length of the wire is short (i.e., less than 15 cm), which is beneficial to reducing the lithography morphology requirements of the upstream lithography process (i.e., the inclination of the etching morphology can be weakly correlated with the inclination of the lithography morphology). BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is a simplified schematic diagram of the structure of the metal etching chamber of the DPS Metal Centura 5200 machine from Applied Materials, Inc.
[0013] Figure 2This is a front view of the fan assembly (Fan Assembly) of the DPS Metal Centura 5200 machine in Example 1 after being removed from the DTCU (Digital Temperature Control Unit).
[0014] Figure 3 yes Figure 2 A top-down physical map.
[0015] Figure 4 This is a photo of the surface roughness of the vanadium oxide film layer of Example 1 before etching
[0016] Figure 5 This is a photograph of the surface roughness of the vanadium oxide film layer of Example 1 after etching.
[0017] Figure 6 This is a SEM slice photograph of the vanadium oxide film layer of Example 1 after etching.
[0018] Figure 7 This is a top view of the DPS Metal Centura 5200 machine of Comparative Example 1 after the fan assembly is removed.
[0019] Figure 8 This is a photograph of the surface roughness of the vanadium oxide film layer of Example 1 after etching.
[0020] Fig. 9 This is a SEM slice photograph of the vanadium oxide film layer of Comparative Example 1 after etching. DETAILED DESCRIPTION
[0021] It will be understood that the disclosed embodiments are merely examples of the present disclosure, which may be implemented in various forms, and therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to implement the present disclosure in various ways.
[0022] [Method of etching vanadium oxide in DPS metal etching chamber]
[0023] Reference Figure 1 Combined with Figure 2 and Figure 3In the method for etching vanadium oxide in a DPS metal etching chamber disclosed in the present invention, the DPS metal etching chamber is a metal etching chamber of a DPS Metal Centura 5200 machine of Applied Materials, Inc., USA. The metal etching chamber of the 5200 machine has a source RF power supply and a bias RF power supply, the source RF power supply is connected to the inductor coil through a wire, and the bias RF power supply is electrically connected to the electrostatic chuck in the chamber of the metal etching chamber; the thermal imaging device to be etched is fixed on the electrostatic chuck, in the thermal imaging device to be etched, the vanadium oxide film layer has been plated on the silicon nitride layer and will be etched, and the thickness of the grown vanadium oxide film layer is controlled to be in the range of 68.5-77.9nm; wherein, the length of the wire is controlled to be greater than 15cm but less than 18cm; when etching the vanadium oxide film layer, the pressure of the chamber is 8-12mT, the source power of the source RF power supply is 400-600W, the bias power of the bias RF power supply is 120-200W, the etching gases introduced into the chamber are Cl2 and Ar, the flow rate of Cl2 is 30-60sccm, the flow rate of Ar is 15-25sccm, the etching time is 15-60s, and the etching rate of the vanadium oxide film layer is The uniformity of the etching rate reaches 6-6.5%, and the surface roughness after etching reaches 0.4-1.0 nm.
[0024] The wire is a special wire for the DPS Metal Centura 5200 machine purchased from Applied Materials, Inc., USA. The source RF power supply is connected to the inductor coil through the wire to form an inductively coupled plasma with the etching process gas introduced into the chamber, and the bias RF power supply is electrically connected to the electrostatic chuck in the chamber of the metal etching chamber to accelerate the inductively coupled plasma.
[0025] In the method of etching vanadium oxide in a DPS metal etching chamber disclosed in the present invention, by controlling the length of the wire between the source RF power supply and the inductor coil of the metal etching chamber of the DPS Metal Centura5200 machine and coordinating the process parameter control for etching the vanadium oxide film layer, the uniformity of the etching rate and the surface roughness of the vanadium oxide film layer can simultaneously reach a high level and the average etching rate can be high.
[0026] In the method of etching vanadium oxide in the DPS metal etching chamber disclosed in the present invention, the morphology of the side wall after etching meets the process requirements, and the inclination angle of the side wall after etching is smaller than that when the length of the wire is short (i.e., less than 15 cm), which is beneficial to reducing the lithography morphology requirements of the upstream lithography process (i.e., the inclination of the etching morphology can be weakly correlated with the inclination of the lithography morphology).
[0027] In one example, the coating of the vanadium oxide film layer is completed by Applied Materials' Centura P5000 equipment; the coating process parameters of the vanadium oxide film layer are: pressure 2-3mT, power 500-600W, Ar assisted coating, Ar flow rate 10-30sccm, voltage 400-450V, time 500-650s.
[0028] In one example, the thickness of the silicon nitride layer is 500-1000 nm. The silicon nitride layer can be formed by chemical vapor deposition using SiH4 and NH3 at 250° C. and 2.2 mF.
[0029] In one example, a silicon substrate is located below the silicon nitride layer.
[0030] [test]
[0031] Example 1
[0032] Example 1 adopts the following method:
[0033] The DPS metal etching chamber is a metal etching chamber of the DPS Metal Centura 5200 machine of Applied Materials, USA. The metal etching chamber of the DPS Metal Centura 5200 machine has a source RF power supply and a bias RF power supply. The source RF power supply is connected to the inductor coil through a wire, and the bias RF power supply is electrically connected to the electrostatic chuck in the chamber of the metal etching chamber. The thermal imaging device to be etched is fixed on the electrostatic chuck. In the thermal imaging device to be etched, the vanadium oxide film layer has been coated on the silicon nitride layer and will be etched. The silicon nitride layer is formed by chemical vapor deposition of SiH4 and NH3 at 250°C and 2.2mT. The thickness of the silicon nitride layer is 800nm. The coating of the vanadium oxide film layer is by Applied Materials' Centura The vanadium oxide film was deposited using a P5000 device. The plating process parameters of the vanadium oxide film were as follows: pressure 2mT, power 550W, Ar assisted plating, Ar flow rate of 10sccm, voltage of 400V, time of 500s, and the thickness of the grown vanadium oxide film was controlled in the range of 68.5-77.9nm; wherein, the length of the wire was controlled to be 17cm; when etching the vanadium oxide film, the chamber pressure was 10mT, the source power of the source RF power supply was 550W, the bias power of the bias RF power supply was 180W, the etching gases introduced into the chamber were Cl2 and Ar, the Cl2 flow rate was 40sccm, the Ar flow rate was 20sccm, and the etching time was 15s.
[0034] Figure 2 This is a front view of the DPS Metal Centura 5200 machine of Example 1 after the fan assembly is removed. Figure 3 yes Figure 1 A top-down physical map.
[0035] Figure 4 is a photograph of the surface roughness of the vanadium oxide film layer of Example 1 before etching. Figure 5 From the Image Ra, we can see that the surface roughness before etching is 0.838nm.
[0036] Figure 5 is a photograph of the surface roughness of the vanadium oxide film layer after etching of Example 1. Figure 5 From the Image Ra, it can be seen that the surface roughness after etching is 0.879nm.
[0037] The surface roughness before and after etching was tested using a BRUKER AFM probe - DDESP-10.
[0038] The average etching rate and uniformity of the etching rate were measured by JA Woollam's spectroscopic ellipsometer-RC2. The average etching rate of the vanadium oxide film layer was The uniformity of the etching rate reaches 6.5%.
[0039] Figure 6 This is a SEM slice photograph of the vanadium oxide film layer of Example 1 after etching. The inclination angle of the side wall after etching is 40.5°.
[0040] Comparative Example 1
[0041] Except that the wire length is 10 cm, the rest is the same as in Example 1.
[0042] Figure 7 This is a top view of the DPS Metal Centura 5200 machine of Comparative Example 1 after the fan assembly is removed.
[0043] Figure 8 This is a photograph of the surface roughness of the vanadium oxide film layer of comparative example 1 after etching. The surface roughness after etching is 0.00168 μm (ie, 1.68 nm).
[0044] In Comparative Example 1, the average etching rate of the vanadium oxide film layer is The uniformity of the etching rate is 10.3%.
[0045] Fig. 9 This is a SEM slice photograph of the vanadium oxide film layer of comparative example 1 after etching. The inclination angle of the side wall after etching is 64.1°.
[0046] The above detailed description is used to describe multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined together to form multiple additional combinations that are not shown for the sake of simplicity.
Claims
1. A method for etching vanadium oxide in a DPS metal etching chamber, characterized in that: The DPS metal etching chamber is the metal etching chamber of the DPS Metal Centura 5200 machine from Applied Materials, Inc. The metal etching chamber of the DPS Metal Centura 5200 machine has a source RF power supply and a bias RF power supply. The source RF power supply is connected to the inductor coil through a wire, and the bias RF power supply is electrically connected to an electrostatic chuck in the chamber of the metal etching chamber. The thermal imaging device to be etched is fixed on an electrostatic chuck. In the thermal imaging device to be etched, a vanadium oxide film layer has been plated on a silicon nitride layer and will be etched. The thickness of the grown vanadium oxide film layer is controlled within a range of 68.5-77.9 nm. The length of the wire is controlled to be greater than 15 cm but less than 18 cm; When etching the vanadium oxide film layer, the pressure of the chamber is 8-12mT, the source power of the source RF power supply is 400-600W, the bias power of the bias RF power supply is 120-200W, the etching gases introduced into the chamber are Cl2 and Ar, the flow rate of Cl2 is 30-60sccm, the flow rate of Ar is 15-25sccm, the etching time is 15-60s, and the etching rate of the vanadium oxide film layer is The uniformity of the etching rate reaches 6-6.5%, and the surface roughness after etching reaches 0.4-1.0 nm.
2. The method for etching vanadium oxide in a DPS metal etching chamber according to claim 1, characterized in that: The vanadium oxide film is deposited using Applied Materials' Centura P5000 equipment; The plating process parameters of the vanadium oxide film layer are: pressure 2-3mT, power 500-600W, Ar assisted plating, Ar flow rate 10-30sccm, voltage 400-450V, time 500-650s.
3. The method for etching vanadium oxide in a DPS metal etching chamber according to claim 1, characterized in that: The thickness of the silicon nitride layer is 500-1000 nm.
4. The method for etching vanadium oxide in a DPS metal etching chamber according to claim 1, characterized in that: The silicon substrate is located below the silicon nitride layer.
5. The method for etching vanadium oxide in a DPS metal etching chamber according to claim 1, characterized in that: The wire is a dedicated wire for a DPS Metal Centura 5200 machine purchased from Applied Materials, Inc., USA.