Reactive ion etching device and method with randomly adjustable removal function

Abstract

The invention discloses a reactive ion etching device and method capable of randomly adjusting a removal function, and belongs to the technical field of surface optical processing, the device comprises a reactive ion etching machine, plasma, a sample to be etched, a movable mask window and a control system; wherein the plasma is located in a vacuum cavity of the reactive ion etching machine and is generated by exciting low-pressure reaction gas through an electromagnetic field, a sample to be etched is located on the surface of an electrode table of the reactive ion etching machine, and the movable mask window is located above the sample to be etched and in the vacuum cavity and is connected with a control system outside the reactive ion etching machine through a cable; the control system controls the position and the moving speed of the moving mask window. Compared with an ion beam polishing technology, local high temperature and surface damage can be effectively avoided, the surface roughness after machining is reduced, and surface optical machining of the flexible material is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of surface optical processing, and in particular relates to a reactive ion etching device and method with an arbitrarily adjustable removal function. Background Art

[0002] In the field of surface optical processing, the industry generally uses ion beam polishing technology based on point scanning path planning, magnetorheological technology and other technologies to perform controllable precision processing of material surface shapes. However, inherent defects such as ion damage and thermal stress deformation limit its application on flexible materials. Existing reactive ion etching technology uses low-temperature and low-stress reactive ion etching technology for surface optical processing of flexible materials. However, it is derived from semiconductor planar processing technology and faces problems such as single removal function and discontinuous surface processing. It cannot be truly applied to the surface optical processing of flexible materials. When traditional plasma etcher is used for curved surface samples, the etching uniformity will decrease due to the uneven longitudinal distribution of plasma concentration. When the size of the plane sample to be engraved is too large, the etching uniformity will also decrease due to the uneven lateral distribution of plasma concentration. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0004] A reactive ion etching device with an arbitrarily adjustable removal function comprises: a reactive ion etcher, a plasma, a sample to be etched, a movable mask window, and a control system; wherein the plasma is located inside a vacuum chamber of the reactive ion etcher and is generated by low-pressure reaction gas excited by an electromagnetic field; the sample to be etched is located on the surface of an electrode stage of the reactive ion etcher; the movable mask window is located above the sample to be etched and inside the vacuum chamber, and is connected to a control system outside the reactive ion etcher via a cable; the control system controls the position and movement speed of the movable mask window.

[0005] A reactive ion etching method with an arbitrarily adjustable removal function, used in the reactive ion etching device with an arbitrarily adjustable removal function, comprising:

[0006] Step 1: Place the sample to be etched on the electrode stage of the reactive ion etcher, insert the movable mask window and connect it to the control system;

[0007] Step 2: Adjust the height of the mask frame so that the mask window maintains an appropriate distance from the surface of the sample to be engraved, and set the motion trajectory parameters of the lateral and longitudinal translation stages according to the required removal function;

[0008] Step 3: evacuate the vacuum chamber of the reactive ion etcher and introduce process gas into the chamber. Turn on the radio frequency power supply to generate plasma and start etching. At the same time, the control system executes the program to control the movement of the mask window.

[0009] Step 4: After etching is completed, turn off the RF power supply, stop introducing the process gas, release the vacuum, and remove the movable mask window and the sample to be etched.

[0010] The present invention has the following beneficial effects:

[0011] (1) Compared with ion beam polishing technology, the present invention can effectively avoid local high temperature and surface damage by utilizing low-temperature and low-stress reactive ions to remove materials, reduce the surface roughness after processing, and realize surface optical processing of flexible materials.

[0012] (2) Compared with the existing reactive ion etching technology, the present invention can effectively solve the problems of single removal function and discontinuous surface processing by setting a moving mask window.

[0013] (3) The present invention is used in planar etching processes, and by regulating the removal function, the uniformity of large-aperture planar and non-planar etching can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the reactive ion etching method with arbitrarily adjustable removal function of the present invention, wherein 1-reactive ion etcher, 2-plasma, 3-sample to be etched, 4-movable mask window, 5-control system;

[0015] Figure 2 This is a partial enlarged view of the mobile mask window, where 4-1 is the mask frame, 4-2 is the mask window, 4-3 is the high-bullet curtain, 4-4 is the horizontal translation stage, and 4-5 is the vertical translation stage. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0017] The technical solution adopted by the present invention to solve the technical problem is: by modifying the traditional reactive ion etcher, a movable mask window 4 is implanted in the vacuum chamber thereof, and the distribution of the plasma 2 on the surface of the sample 3 to be etched is modulated by controlling the position and speed of the movable mask window 4 (the removal function is regulated by controlling the position and speed of the movable mask window 4 to achieve the distribution of the plasma 2 on the surface of the sample 3 to be etched), thereby achieving arbitrary adjustment of the removal function of the reactive ion etcher 1.

[0018] like Figure 1As shown, the reactive ion etching device with an arbitrarily adjustable removal function of the present invention includes a reactive ion etcher 1, a plasma 2, a sample to be etched 3, a movable mask window 4, and a control system 5. Among them, the plasma 2 is located inside the vacuum chamber of the reactive ion etcher 1 and is generated by low-pressure reaction gas excited by an electromagnetic field. The sample to be etched 3 is located on the surface of the electrode stage of the reactive ion etcher 1 (the electrode stage is one of the standard components of the reactive ion etcher 1). The movable mask window 4 is located above the sample to be etched 3 and inside the vacuum chamber, and is connected to the control system 5 outside the reactive ion etcher 1 via a cable. Figure 2 As shown, the movable mask window 4 includes a mask frame 4-1, a mask window 4-2, a high-bullet curtain 4-3, a lateral displacement stage 4-4 and a longitudinal displacement stage 4-5; the mask frame 4-1 is fixedly connected to the inside of the vacuum chamber, the mask window 4-2 is vertically connected to the lateral displacement stage 4-4, the lateral displacement stage 4-4 is connected to the longitudinal displacement stage 4-5, and the longitudinal displacement stage 4-5 is connected to the mask frame 4-1.

[0019] The reactive ion etcher 1 is used for the pattern etching and transfer process of planar devices such as silicon, silicon oxide, silicon nitride and other planar substrates. It mainly includes a vacuum chamber, a radio frequency power supply, an electrode stage, a process gas intake system, a vacuum exhaust system and other parts. The working process is to place the sample to be etched on the electrode stage, then evacuate the vacuum and introduce the process gas, turn on the radio frequency power supply to generate plasma and start etching, turn off the radio frequency power supply after completion, stop introducing the process gas, and finally release the vacuum to remove the sample.

[0020] The plasma 2 is generated within the vacuum chamber of the reactive ion etcher 1 by energizing the process gas with an RF power supply. Normally, the plasma 2 is evenly distributed laterally within the chamber, with a higher concentration in the longitudinal region near the lower electrode stage. The plasma is not static, but rather diffuses from the air inlet throughout the chamber. The plasma 2, in contact with the sample 3 to be etched, undergoes a chemical reaction to generate volatile gases. Finally, both the reacting and unreacting gases are extracted from the vacuum pumping system through the exhaust port. If there is an obstruction on the surface of the sample 3 to be etched, the plasma concentration in the obstructed area is reduced, thereby reducing the etching rate.

[0021] The sample 3 to be engraved includes all materials that can react with plasma, such as semiconductor materials, optical quartz materials, flexible plastic materials, etc. The shape of the sample is not limited to a plane, but can also be a curved surface.

[0022] The movable mask window 4 is the core of the present method, and is mainly composed of a mask frame 4-1, a mask window 4-2, a high-bullet curtain 4-3, a lateral displacement stage 4-4, and a longitudinal displacement stage 4-5. The position and movement speed of the movable mask window 4 are controlled by a control system 5. The mask frame 4-1 is connected to the vacuum chamber of the reactive ion etcher 1 and supports the entire movable mask window 4. The lateral displacement stage 4-4 and the longitudinal displacement stage 4-5 are located above the mask frame 4-1, the mask window 4-2 is connected to the lateral displacement stage 4-4, and the high-bullet curtain 4-3 covers the area from the outer edge of the mask window 4-2 to the inner edge of the mask frame 4-1. The plasma 2 can only pass through the mask window 4-2 to reach the surface of the sample 3 to be engraved. Therefore, the concentration of the plasma 2 below the mask window 4-2 is the highest and the etching rate is the fastest. In the area deviating from the mask window 4-2, the concentration of the plasma 2 and the etching rate decrease exponentially.

[0023] The mask frame 4-1 is made of an insulating material or a material covered with an insulating layer to avoid significantly affecting the electromagnetic field within the reactive ion etcher 1. The aperture of the mask frame 4-1 is larger than the aperture of the electrode stage of the reactive ion etcher 1. The plasma 2 flow path passes through either the mask window 4-2 or the outside of the mask frame 4-1. The position of the mask frame 4-1 can be manually adjusted, allowing the distance between the mask window 4-2 and the sample 3 to be engraved to be greater or lesser, with an adjustment range of greater than 100 mm to accommodate samples 3 of varying thickness and shape.

[0024] The mask window 4-2 is also made of an insulating material or a material covered with an insulating layer. Its size is adjustable, from a minimum of 5 mm to a maximum of 100 mm, to accommodate varying processing requirements for high-frequency and low-frequency errors. The mask window 4-2 is connected to the lateral translation stage 4-4 via an insulating bracket. The mask window 4-2 is flush with or below the plane of the mask frame 4-1. The distance between the mask window 4-2 and the surface of the sample 3 to be engraved is adjustable from 2 mm to 20 mm.

[0025] The high-barrel screen 4-3 is made of an elastic film or fiber material with a low outgassing rate. This material exhibits sufficient elasticity to accommodate the tensile deformation caused by the movement of the mask window 4-2 within the entire electrode stage area of ​​the reactive ion etcher 1. The average pore size of the high-barrel screen 4-3 is less than 10 microns, making it difficult for plasma 2 to penetrate the screen 4-3 and reach the sample to be engraved. Even if plasma 2 can penetrate the screen 4-3, the penetration rate is almost negligible.

[0026] Both the transverse and longitudinal stages 4-4 and 4-5 are vacuum motorized stages with surface insulation to minimize their impact on the electromagnetic field within the vacuum chamber of the reactive ion etcher 1. The longitudinal stage 4-5 is mounted on the mask frame 4-1, while the transverse stage frame 4-4 is mounted on the longitudinal stage 4-5. The overall thickness from the lower surface of the mask window 4-2 to the upper surface of the transverse stage 4-4 is less than 30 mm, and the upper surface of the transverse stage 4-4 is greater than 30 mm from the process gas inlet.

[0027] The reactive ion etching method of the present invention with an arbitrarily adjustable removal function comprises:

[0028] Step 1: Place the sample 3 to be etched on the electrode stage of the reactive ion etcher 1, insert the movable mask window 4 and connect it to the control system;

[0029] Step 2: Adjust the height of the mask frame 4-1 so that the mask window 4-2 maintains a suitable distance from the surface of the sample 3 to be engraved, and set the motion trajectory parameters of the lateral displacement stage 4-4 and the longitudinal displacement stage 4-5 according to the required removal function;

[0030] Step 3: evacuate the vacuum chamber of the reactive ion etcher 1 and introduce process gas into the chamber. Turn on the radio frequency power supply to generate plasma and start etching. At the same time, the control system 5 executes a program to control the movement of the mask window 4-2.

[0031] Step 4: After etching is completed, turn off the RF power supply, stop introducing the process gas, release the vacuum, and take out the movable mask window 4 and the sample 3 to be etched.

[0032] The above descriptions are merely embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied to other related system fields, are also included in the scope of protection of the present invention.

[0033] The contents not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

Claims

1. A reactive ion etching device with an arbitrarily adjustable removal function, characterized in that: include: A reactive ion etcher, plasma, a sample to be etcher, a movable mask window, and a control system; wherein the plasma is located inside the vacuum chamber of the reactive ion etcher and is generated by low-pressure reaction gas excited by an electromagnetic field; the sample to be etcher is located on the surface of the electrode stage of the reactive ion etcher; the movable mask window is located above the sample to be etcher and inside the vacuum chamber, and is connected to a control system outside the reactive ion etcher via a cable; the control system controls the position and movement speed of the movable mask window.

2. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The movable mask window includes a mask frame, a mask window, a high-elasticity curtain, a lateral displacement stage and a longitudinal displacement stage; the mask frame is fixedly connected to the inside of the vacuum chamber of the reactive ion etcher, the mask window is connected to the lateral displacement stage, the lateral displacement stage is vertically connected to the longitudinal displacement stage, and the longitudinal displacement stage is connected to the mask frame.

3. The reactive ion etching device with arbitrarily adjustable removal function according to claim 2, characterized in that: The mask frame is connected to the vacuum chamber of the reactive ion etcher, supporting the entire movable mask window; the lateral and longitudinal translation stages are located on the mask frame, the mask window is connected to the lateral translation stage, and the high-bullet curtain covers the area from the outer edge of the mask window to the inner edge of the mask frame; the plasma can only pass through the mask window to reach the surface of the sample to be etched.

4. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The plasma is generated by exciting the process gas with a radio frequency power supply, and is evenly distributed laterally in the cavity, with a higher concentration in the longitudinal area of ​​the reactive ion etcher near the lower electrode stage; the plasma diffuses from the air inlet to the entire cavity, and the plasma in contact with the sample to be etched undergoes a chemical reaction to generate volatile gases, and both the gases involved in the reaction and those not involved in the reaction are extracted from the vacuum exhaust port by the vacuum exhaust system.

5. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The sample to be engraved is a semiconductor material that can react with plasma, an optical quartz material, a flexible plastic material or other materials that can react with plasma.

6. The reactive ion etching device with arbitrarily adjustable removal function according to claim 2 or 3, characterized in that: The mask frame is made of insulating material or a material covered with an insulating layer; the position of the mask frame is adjusted to match samples to be engraved with different thicknesses and shapes.

7. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The mask window is made of insulating material or a material covered with an insulating layer. The size of the mask window is adjustable to adapt to different processing requirements of high-frequency error and low-frequency error. The mask window is connected to the lateral translation stage through an insulating bracket. The mask window and the mask frame are in the same plane or lower than the plane of the mask frame. The distance between the mask window and the surface of the sample to be engraved is adjustable.

8. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The high-bullet curtain is made of elastic film or fiber material with low degassing rate.

9. The reactive ion etching device with arbitrarily adjustable removal function according to claim 1, characterized in that: The lateral displacement stage and the longitudinal displacement stage are both vacuum electric displacement stages with surface insulation treatment; the longitudinal displacement stage is mounted on the mask frame, and the lateral displacement stage is mounted on the longitudinal displacement stage.

10. A reactive ion etching method with an arbitrarily adjustable removal function, used in the reactive ion etching device with an arbitrarily adjustable removal function according to any one of claims 1 to 9, characterized in that: include: Step 1: Place the sample to be etched on the electrode stage of the reactive ion etcher, insert the movable mask window and connect it to the control system; Step 2: Adjust the height of the mask frame so that the mask window maintains an appropriate distance from the surface of the sample to be engraved, and set the motion trajectory parameters of the lateral and longitudinal translation stages according to the required removal function; Step 3: evacuate the vacuum chamber of the reactive ion etcher and introduce process gas into the chamber. Turn on the radio frequency power supply to generate plasma and start etching. At the same time, the control system executes the program to control the movement of the mask window. Step 4: After etching is completed, turn off the RF power supply, stop introducing the process gas, release the vacuum, and remove the movable mask window and the sample to be etched.

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