Hard mask preparation method suitable for high aspect ratio etching of metasurface structure

Abstract

The invention relates to a hard mask preparation method suitable for super surface structure high aspect ratio etching, and belongs to the technical field of hard mask preparation, and the hard mask preparation method comprises the following steps: S1, guaranteeing the quality of a film material and the cleanliness of a cavity, carrying out two-stage pre-melting on a large-capacity crucible by using a combined light spot pre-melting film material means, and carrying out two-stage pre-melting on the large-capacity crucible; and finally, stable deposition is carried out by adopting a non-oscillation point light spot. S2, according to different film materials, after proper electron beam power is determined, sufficient heating and continuous heating are guaranteed at a slow temperature rise time and a stable temperature for a period of time until the process is finished, then the deposition rate is adjusted, and a low-roughness film is deposited at a low rate; and S3, preparing the metal film by using the method, and applying the prepared metal film to different metasurface structures for high aspect ratio etching. The stable energy exchange between the electron beam and the film material is controlled by adjusting the light spot type and power of the electron beam, so that the premelting stability of the film material is realized.

Description

Technical Field

[0001] The present invention belongs to the field of hard mask preparation, and in particular relates to a hard mask preparation method suitable for high aspect ratio etching of a super surface structure. Background Art

[0002] At present, the electron beam spot types of mass-produced vacuum evaporation equipment are relatively few, and the temperature variation of the chamber is uneven. This method is inefficient and requires high equipment control, and it is difficult to achieve a high-quality metal mask layer for small-size high aspect ratio etching. Summary of the invention

[0003] The present application provides a hard mask preparation method suitable for high aspect ratio etching of super surface structures, so as to at least solve the above technical problems existing in the prior art.

[0004] The present application provides a method for preparing a hard mask suitable for etching a super surface structure with a high aspect ratio, comprising the following steps: S1. To ensure the quality of the film material and the cleanliness of the chamber, a combined light spot pre-melting method is used for large-capacity crucibles. First, a light spot with large oscillation in the X and Y directions is used with an electron gun power lower than the normal process to scan the film material surface for 40 seconds. Then, a light spot with smaller oscillation in the X and Y directions is used for second-stage pre-melting. At this time, the electron gun power should be close to the electron gun power of the normal process to scan the film material surface for 30 seconds. Finally, a non-oscillating point light spot is used for stable deposition. S2. After determining the appropriate electron beam power according to different film materials, determine the initial temperature of the substrate surface according to the heat change of the equipment during the deposition process, with a slower heating time. At the same time, the temperature must be stable for a period of time to ensure sufficient heating and heating continues until the end of the process. Then adjust the deposition rate and use a lower rate to deposit a low-roughness film; S3. Prepare a metal film using the above method, and apply the prepared metal film to different super-surface structures for high aspect ratio etching.

[0005] In one embodiment, the temperature in S2 is stabilized to 30-100°C, the heating time is 10-30 min, and the rate is <1 Å / s.

[0006] In one embodiment, the temperature in S2 is stabilized to 40-80°C, the heating time is 10-30 min, and the rate is <1 Å / s.

[0007] In one embodiment, the temperature in S2 is stabilized to 30-60°C, the heating time is 10-30 min, and the rate is <1 Å / s.

[0008] In one embodiment, the temperature in S2 is stabilized to 60-100°C, the heating time is 10-30 min, and the rate is <1 Å / s.

[0009] In one embodiment, the temperature in S2 is stabilized to 40°C, the temperature is maintained for 20 minutes, the rate is 0.6Å / s, and a vacuum degree of less than 5E-4 is used.

[0010] In one embodiment, the temperature in S2 is stabilized to 80°C, the temperature is maintained for 20 minutes, the rate is 0.6Å / s, and a vacuum degree of less than 5E-4 is used.

[0011] In one embodiment, the temperature in S2 is stabilized to 50-60°C, the heating time is 10-30 min, and the rate is <1 Å / s.

[0012] In one possible implementation, in S1, a lower electron gun power of X=5, Y=5 is first used for spot oscillation for the first stage of pre-melting, and then a spot oscillation of X=2, Y=2 is used for the second stage of pre-melting at a power close to the evaporation rate.

[0013] In one possible implementation, in S1, a lower electron gun power of X=5, Y=5 is first used for spot oscillation for the first stage of pre-melting, and then a spot oscillation of X=2, Y=2 is used for the second stage of pre-melting at a power close to the evaporation rate.

[0014] Compared with the prior art, this application has the following advantages: The present application achieves stable pre-melting of the film material by adjusting the electron beam spot type and power to control the stable energy exchange between the electron beam and the film material; The present application controls the temperature to adjust the stress and strain of the metal film caused by the limitation of the equipment, thereby achieving constant temperature at the base plate, the crucible and the chamber, thereby effectively reducing the roughness and increasing the density. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Electron microscope image of the end surface of the film in Example 1 of the present application; Figure 2 Schematic diagram of the surface roughness of the film in Example 1 of the present application; Figure 3 Electron microscope image of the end surface of the film in Example 2 of the present application; Figure 4 Schematic diagram of the surface roughness of the film in Example 2 of the present application; Figure 5 An electron microscope image of the end surface of the film in comparative example 1 of the present application. Implementation

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0017] The present application discloses a method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio, comprising the following steps: S1. To ensure the quality of the film material and the cleanliness of the chamber, a combined light spot pre-melting method is used for large-capacity crucibles. First, a light spot with large oscillation in the X and Y directions is used with an electron gun power lower than the normal process to scan the film surface for 40 seconds. Then, a smaller oscillating light spot in the X and Y directions is used for the second-stage pre-melting. At this time, the electron gun power should be close to the electron gun power of the normal process to scan the film surface for 30 seconds. Finally, a non-oscillating point light spot is used for stable deposition.

[0018] It should be noted that a smaller oscillating spot in the X and Y directions is used, that is, the spot of the second oscillation is smaller than the spot of the first oscillation. In the second oscillation, the value of X and / or Y can be 0, that is, a point spot or a line spot can be used.

[0019] S2. After determining the appropriate electron beam power according to different film materials, determine the initial temperature of the substrate surface according to the heat change of the equipment during the deposition process, with a slower heating time. At the same time, the temperature must be stable for a period of time to ensure sufficient heating and heating continues until the end of the process. Then adjust the deposition rate and use a lower rate to deposit a low-roughness film.

[0020] In order to further increase the purity of the film and reduce impurities and defects, vacuuming is used in this step.

[0021] S3. Prepare a metal film using the above method, and apply the prepared metal film to different super-surface structures for high aspect ratio etching. Example

[0022] The steps of the hard mask preparation method in this embodiment are as follows: 1. Under the premise of ensuring the quality of the film material and the cleanliness of the chamber, the vacuum degree is controlled at 5E-4, the evaporation tray is heated to 40℃ and maintained for 20 minutes, and then a lower electron gun power and a spot oscillation of X=5, Y=5 are used for the first pre-melting, and then a spot oscillation of X=2, Y=2 is used for the second pre-melting at a power close to the evaporation rate, and finally a point spot is used for stable deposition.

[0023] 2. Use a deposition rate of 0.6Å / s for stable evaporation.

[0024] Figure 2 Schematic diagram of the measured surface roughness, the roughness is 0.5.

[0025] Depend on Figure 1 and Figure 2 It can be seen that the film prepared in this embodiment has good density, uniform surface and low roughness. Example

[0026] The difference between this embodiment and embodiment 1 is that the temperature of heating is different, and the steps are as follows: 1. Under the premise of ensuring the quality of the film material and the cleanliness of the chamber, the vacuum degree is controlled at 5E-4, the evaporation tray is first heated to 80℃ and maintained for 20 minutes, and then a lower electron gun power and a spot oscillation of X=5, Y=5 are used for the first pre-melting, and then a spot oscillation of X=2, Y=2 is used for the second pre-melting at a power close to the evaporation rate, and finally a point spot is used for stable deposition.

[0027] 2. Use a deposition rate of 0.6Å / s for stable evaporation.

[0028] Figure 4 This is a schematic diagram of the measured surface roughness, and the roughness is 0.35.

[0029] Depend on Figure 3 and Figure 4 It can be seen that the film prepared in this embodiment has good density, uniform surface and low roughness. The roughness of this embodiment is less than that of embodiment 1.

[0030] Comparative Example 1 The difference between the comparative embodiment 1 and other embodiments is that the oscillating light spots are different.

[0031] A method for preparing a hard mask suitable for etching a super surface structure with a high aspect ratio, comprising the following preparation steps: 1. Under the premise of ensuring the quality of the film material and the cleanliness of the chamber, the pre-melting and the start of evaporation use a spot oscillation smaller than the edge of the crucible (X=3, Y=3) to ensure the uniformity of the melt, and finally use a point spot for stable deposition.

[0032] 2. Use a vacuum degree below 5E-4 and an evaporation rate of 1Å / s for stable evaporation.

[0033] Depend on Figure 5 It can be seen that the film prepared in this comparative example has poor compactness, a loose surface and holes. The roughness of the film is 3.3.

[0034] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio, characterized in that: The steps include: S1. To ensure the quality of the film material and the cleanliness of the chamber, a combined light spot pre-melting method is used for large-capacity crucibles. First, a light spot with large oscillation in the X and Y directions is used with an electron gun power lower than the normal process to scan the film material surface for 40 seconds. Then, a light spot with smaller oscillation in the X and Y directions is used for second-stage pre-melting. At this time, the electron gun power should be close to the electron gun power of the normal process to scan the film material surface for 30 seconds. Finally, a non-oscillating point light spot is used for stable deposition. S2. After determining the appropriate electron beam power according to different film materials, determine the initial temperature of the substrate surface according to the heat change of the equipment during the deposition process, with a slower heating time. At the same time, the temperature must be stable for a period of time to ensure sufficient heating and heating continues until the end of the process. Then adjust the deposition rate and use a lower rate to deposit a low-roughness film; S3. Prepare a metal film using the above method, and apply the prepared metal film to different super-surface structures for high aspect ratio etching.

2. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 1, characterized in that: The temperature in S2 is stabilized to 30~100℃, the heating time is 10~30min, and the rate is <1Å / s.

3. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 1, characterized in that: The temperature in S2 is stabilized to 40~80℃, the heating time is 10~30min, and the rate is <1Å / s.

4. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 1, characterized in that: The temperature in S2 is stabilized to 30~60℃, the heating time is 10~30min, and the rate is <1Å / s.

5. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 1, characterized in that: The temperature in S2 is stabilized to 60~100℃, the heating time is 10~30min, and the rate is <1Å / s.

6. A method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to any one of claims 1 to 4, characterized in that: The temperature in S2 was stabilized to 40 °C and maintained for 20 min at a rate of 0.6 Å / s using a vacuum less than 5E-4.

7. A method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to any one of claims 1 to 3 and 5, characterized in that: The temperature in S2 was stabilized to 80 °C and maintained for 20 min at a rate of 0.6 Å / s using a vacuum less than 5E-4.

8. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 1, characterized in that: The temperature in S2 is stabilized to 50~60℃, the heating time is 10~30min, and the rate is <1Å / s.

9. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 6, characterized in that: In S1, a relatively low electron gun power of X=5, Y=5 is first used for spot oscillation for the first stage of pre-melting, and then a spot oscillation of X=2, Y=2 is used for a power close to the evaporation rate for the second stage of pre-melting.

10. The method for preparing a hard mask suitable for etching of a super surface structure with a high aspect ratio according to claim 7, characterized in that: In S1, a relatively low electron gun power of X=5, Y=5 is first used for spot oscillation for the first stage of pre-melting, and then a spot oscillation of X=2, Y=2 is used for a power close to the evaporation rate for the second stage of pre-melting.

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