KR102396234B1 - Wafer etching shower head manufacturing method - Google Patents

Abstract

The present invention comprises the steps of a) preparing a cylindrical ingot, b) cropping the ingot into a base material of a corresponding length unit, and c) slicing the base material cropped in a corresponding length unit into a base material disc of the corresponding thickness. step, d) surface processing of the base material disk sliced to the corresponding thickness, e) after placing the electrode at the corresponding position on the surface-processed base material disk, an electric discharge is generated between the base material disk and the electrode A step of forming a plurality of micro-holes by drilling electric discharge machining, and f) washing the base material disk in which a plurality of micro-holes are formed. A wafer etching showerhead manufacturing method is provided for manufacturing a showerhead for wafer etching by placing an electrode at a corresponding position on the processed base material, and then forming a number of fine holes by electric discharge machining to generate an electric discharge and drilling. do.

Description

Wafer etching shower head manufacturing method

The present invention relates to a method for manufacturing a wafer etching showerhead, and more particularly, after forming micro-holes in a processing disk by electric discharge machining, re-applying power without electrode wear, or applying power without electrode wear again, A wafer etching showerhead with improved surface roughness on the inner circumferential surface of the micro-hole by rotating the center about the axis or rotating the electrode along the inner circumferential surface with the center of the micro-hole as the axis while applying power without electrode wear again It relates to a method for manufacturing a wafer etching showerhead.

In general, a showerhead for semiconductor etching is equipment used to etch a wafer by spraying a plasma gas from a semiconductor manufacturing chamber to a silicon wafer.

The showerhead has a plurality of gas injection holes, and the gas in a plasma state passes through the gas injection holes. In order to precisely etch the wafer, the hole in the showerhead must be precisely created.

To this end, as in Prior Document 1 (Republic of Korea Patent No. 10-0299975) and Prior Document 2 (Republic of Korea Patent No. 10-0935418), a circular plate made of abrasive and silicon material is opposed to a drinking ring plate in which a plurality of tips protrude, and , while supplying an abrasive to the drilling plate and the disc, ultrasonic waves were applied to the drilling plate to perforate the disc.

However, in Prior Documents 1 and 2, the length of the pin inserted into the drilling plate becomes longer when processing a thick showerhead. This causes the fins to vibrate when ultrasonic waves are generated, causing a problem in that the holes of the showerhead are not uniformly formed.

In particular, in the case of silicon carbide (Sic), in which silicon (Si) and carbon (C) are bonded in a 1:1 ratio, it is a strong covalent material and has high thermal conductivity compared to other ceramic materials, abrasion resistance, high temperature strength and resistance. Because of its excellent chemical properties, it is widely applied to reinforce, supplement, or replace it in fields that are weak or essential in terms of mechanical properties.

However, when manufacturing a showerhead electrode using silicon carbide, a plurality of through holes can be formed using an artificial diamond drill due to high Mohs hardness. In addition, it is difficult to simultaneously form a plurality of through-holes, and when the size or location of one through-hole is out of a predetermined standard, the entire product must be discarded, which may cause a problem in that the production yield is significantly lowered.

In addition, since the surface roughness of the processed hole is not uniform, if the size or location of the hole is out of a predetermined standard, the entire product must be discarded, which may cause a problem in that the production yield is significantly lowered.

In the present invention, after forming micro-holes in the machining disk by electric discharge machining, the power supply without electrode wear is applied again, or the electrode is rotated about the center of the electrode while applying power without electrode wear again, or the electrode wear is reduced. To provide a method for manufacturing a wafer etching showerhead that provides a wafer etching showerhead with improved surface roughness on the inner circumferential surface of the microhole by rotating the electrode along the inner circumferential surface with the center of the microhole as the axis while re-applying no power do.

A method for manufacturing a wafer etching showerhead according to the present invention includes: a) preparing a cylindrical ingot; b) cropping the ingot to a base material of a corresponding length unit; c) a base material cropped by a corresponding length unit The steps of slicing into a base plate of the corresponding thickness, d) processing the surface of the base plate sliced to the corresponding thickness, and e) After placing the electrode of the electric discharge machine on the base plate with the surface processed at the corresponding position, A step of forming a plurality of micro-holes by electric discharge machining of drilling by applying a primary power source to the electrode to generate an electric discharge, and f) washing the base plate having the plurality of micro-holes formed therein.

At this time, in the step d) according to the present invention, in the step of surface processing of the base material disk sliced to the corresponding thickness, the upper and lower surfaces of the base material disk are processed with a surface grinder, and the side surface of the base material disk is processed with a CNC grinder.

And it is preferable that the primary power source according to the present invention has a frequency of 18 to 83 KHz, a voltage width of 90 to 100 Vp-p, and an output current of 3 to 57 A.

In addition, in step e) according to the present invention, after arranging the electrode at the corresponding position on the surface-processed base material disk, the primary power is applied to the electrode to generate an electric discharge and drilling a plurality of micro-holes In the step of forming, after locating the electrode in the center of the microhole formed by electric discharge machining, applying a secondary power to the electrode, and improving the surface roughness of the inner peripheral surface of the microhole by discharging by the secondary power. include

Here, the secondary power source according to the present invention preferably has a frequency of 1 to 10 MHz, a voltage width of 10 to 100 Vp-p, and an output current of 100 mA or less.

In addition, when improving the surface roughness of the inner circumferential surface of the microhole by the discharge by the secondary power source according to the present invention, the electrode can improve the surface roughness of the inner circumferential surface of the microhole while axially rotating about the center of the electrode.

In addition, when the surface roughness of the inner circumferential surface of the micro-hole is improved by the discharge by the secondary power source according to the present invention, the electrode rotates along the inner circumferential surface of the micro-hole with the center of the micro-hole as an axis, and the surface roughness of the inner circumferential surface of the micro-hole can be improved

And in the step f) according to the present invention, in the step of washing the base plate having a plurality of micro-holes formed by hole processing, the abrasive is passed through the micro-holes formed in the base plate by hydraulic pressure, and the inner circumferential surface of the micro-holes is applied to the and post-processing by grinding with an abrasive.

In this case, the abrasive according to the present invention is preferably in the form of a gel including silicon carbide (SiC) or diamond powder and a binder.

In addition, in the step f) according to the present invention, in the step of washing the base plate having a plurality of micro-holes formed by hole machining, the base plate is immersed in a water tank containing a solvent to remove the powder generated in the base plate during electric discharge machining. The method further includes the steps of removing by melting and cleaning the base plate with ultrasonic waves by applying ultrasonic waves to the water bath containing the solvent.

Effects of the wafer etching showerhead manufacturing method according to the present invention are as follows.

After forming micro-holes in the machining disk by electric discharge machining, re-apply power without electrode wear, or rotate the center of the electrode around the axis while re-applying power without electrode wear, or turn on power without electrode wear. As the electrode is rotated along the inner circumferential surface with the center of the micro-hole as an axis while re-applied, it has the effect of providing a wafer etching showerhead with improved surface roughness on the inner circumferential surface of the micro-hole.

1 is a schematic diagram illustrating a method of manufacturing a wafer etching showerhead according to an embodiment of the present invention.
2 is an exemplary view showing a state of improving the surface roughness of the inner peripheral surface of the micro-hole according to an embodiment of the present invention.
3 is an exemplary view showing a state of improving the surface roughness of the inner peripheral surface of the micro-hole by pressing an abrasive according to an embodiment of the present invention.
4 is an exemplary view briefly showing a method of manufacturing a wafer etching showerhead according to another embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention. It should be understood that there may be variations.

In the present invention, after forming micro-holes in the machining disk by electric discharge machining, the power supply without electrode wear is applied again, or the electrode is rotated about the center of the electrode while applying power without electrode wear again, or the electrode wear is reduced. It relates to a method of manufacturing a wafer etching showerhead that provides a wafer etching showerhead with improved surface roughness on the inner circumferential surface of the microhole by rotating the electrode along the inner circumferential surface with the center of the microhole as the axis while re-applying no power. In more detail with reference to the following.

In step a) of the method for manufacturing a wafer etching showerhead according to an embodiment of the present invention with reference to FIGS. 1 to 3 , first, cylindrical silicon (Si) or aluminum (Al) or silicon (Si) or aluminum (Al) To prepare an ingot (ingot: 10) made of oxide, carbide (silicon carbide (Sic)), nitride combined with oxygen, carbon, nitrogen, and the like.

At this time, the prepared ingot 10 is pure silicon (Si) or aluminum (Al) or silicon (Si) or aluminum (Al) without impurities combined with oxygen, carbon, nitrogen, etc., oxide, carbide (silicon carbide (Sic)) ), as a nitride mass, the ingot 10 preferably forms a cylindrical shape to facilitate obtaining a disk.

Then, in step b), the ingot 10 is cropped with the base material 11 of the corresponding length unit.

At this time, the ingot 10 prepared by step a) is cut into a predetermined unit of length and divided into equal parts into base materials 11 of the corresponding length units, and the divided base material 11 is easily processed into a base material plate 20 It is preferable to form a cylindrical shape.

Then, in step c), the cropped base material 11 is sliced into the base material disk 20 of the corresponding thickness.

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Ωcm로 두께로 슬라이싱하는 것이 바람직하다.At this time, the base material 11 cropped by step b) is such that the base material disk 20 has a low resistance (3Ω or less).

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It is preferable to slice to thickness in Ωcm.

Then, in step d), the surface of the base material disk 20 sliced to the corresponding thickness is processed.

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Ωcm로 두께로 슬라이싱된 상기 모재원판(20)의 표면 중 상, 하면은 서피스 그라인더(100)로 표면을 가공하고, 상기 모재원판 중 측면(외주면)은 CNC그라인더(200)로 표면을 가공한다.At this time, to have a low resistance (3Ω or less) in step c)

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Among the surfaces of the base material disk 20 sliced to a thickness of Ωcm, the upper and lower surfaces are processed with a surface grinder 100, and the side (outer peripheral surface) of the base material disk is processed with a CNC grinder 200.

And the next step is e), after placing the electrode 300 on the base material disk 20 with the surface processed at the corresponding position, and then drilling by generating an electric discharge between the base material disk 20 and the electrode 300 A plurality of micro-holes 21 are formed by electric discharge machining.

At this time, a plurality of micro-holes 21 are formed by electric discharge machining in the base material disk 20 whose surface is processed in step d). After disposing in the corresponding position, by applying a primary power to the electrode (300) to generate an electric discharge between the base plate (20) and the electrode (300) is drilled.

Here, the primary power source has a frequency of 18 to 83 KHz, a voltage width of 90 to 100 Vp-p, and an output current of 3 to 57 A, preferably, a plurality of fine holes 21 in the base plate 20. In order to form it, it is preferable to continuously and repeatedly perform movement and discharge of the electrode 300 .

And in the wafer etching showerhead manufacturing method according to an embodiment of the present invention, when the micro-holes 21 are formed in the base plate 20 by electric discharge machining, the purpose of improving the surface roughness of the inner peripheral surface of the micro-holes 21 As a result, after positioning the electrode 300 in the center of the micro-hole 21 formed by electric discharge machining, a secondary power source is applied to the electrode 300 to a degree that does not cause electrode abrasion, and the secondary power supply By arranging the inner circumferential surface of the micro-holes 21 by the discharge, the surface roughness of the inner circumferential surface of the micro-holes 21 is improved.

At this time, it is preferable that the secondary power source has a frequency of 1 to 10 MHz, a voltage width of 10 to 100 Vp-p, and an output current of 100 mA or less. In the case of frequency, it is also possible to automatically select an optimal value according to the processing condition.

In addition, when the surface roughness of the inner circumferential surface of the micro-hole 21 is improved by discharging by the secondary power source, the electrode 300 rotates about the center of the micro-hole 21 while discharging by the secondary power source. ) can improve the surface roughness of the inner peripheral surface.

In addition, when the surface roughness of the inner circumferential surface of the micro-hole 21 is improved by discharging by the secondary power source, the electrode 300 is discharged by the secondary power source while the micro-hole 21 is the center of the micro-hole as an axis. While rotating along the inner circumferential surface of (21), the surface roughness of the inner circumferential surface of the fine hole 21 may be improved.

Then, in step f), the base material disk 20 on which the plurality of microholes 21 are formed is washed.

At this time, the step of washing the base material disk 20 on which the microholes 21 are formed by step e) includes a post-processing step, wherein the post-processing is performed by inserting the abrasive material 401 into the micro-holes 21 formed in the base material disk 20 . ), and grinding the inner peripheral surface of the micro-holes 21 with the abrasive 401 to improve the surface roughness of the inner peripheral surfaces of the micro-holes 21 .

Here, the abrasive 401 is in the form of a gel containing silicon carbide (SiC) or diamond powder and a binder, and the abrasive 401 is selectively moved from one side to the other or the other side by a linear motion of a piston operated by hydraulic pressure. In the flow to one side, for example, after disposing the base material disk 20 having the micro-holes 21 formed between the pipes in which the abrasive 401 moves linearly, pressure is applied to the abrasive material 401 with a piston to apply pressure to the base material. The abrasive material 401 is allowed to pass through the microholes 21 of the disk 20, and the abrasive material 401 is continuously and repeatedly flowed from one side to the other side or from the other side to one side, and the inner circumferential surface of the microholes 21 to improve the surface roughness of the inner peripheral surface of the micro-holes 21 by grinding with a continuous and repeated flow of the abrasive 401 .

And the base material disk 20, which has finished post-processing, is immersed in a water tank 500 containing a solvent to melt and remove the powder generated in the base material disk 20 during electric discharge machining.

In addition, the showerhead for wafer etching can be completed by applying ultrasonic waves to the tank 500 in which the solvent is accommodated and cleaning the base plate 200 with ultrasonic waves.

4, in an embodiment of the present invention, the post-processing is described as being performed before washing with a solvent, but the present invention is not limited thereto, and the post-processing may be performed after washing with a solvent.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: ingot
11: base material
20: base plate
21: fine hole
100: surface grinder
200: CNC grinder
300: electrode of electric discharge machine
401: abrasive
500: tank

Claims (10)

a) preparing a cylindrical ingot;
b) cropping the ingot to a base material of a corresponding length unit;
c) slicing the base material cropped by the corresponding length unit into a base material disc of the corresponding thickness:
d) surface processing of the base plate sliced to the corresponding thickness;
e) forming a plurality of micro-holes by electric discharge machining in which the electrode of the electric discharge machine is placed at the corresponding position on the surface-processed base plate, and then an electric discharge is generated by applying a primary power to the electrode; and
f) washing the base plate having a plurality of micro-holes formed therein;
The primary power is
A method of manufacturing a wafer etching showerhead with a frequency of 18 to 83 KHz, a voltage width of 90 to 100 Vp-p, and an output current of 3 to 57 A.
The method according to claim 1,
In the step d), in the step of surface processing of the base material plate sliced to the corresponding thickness,
A wafer etching showerhead manufacturing method in which the upper and lower surfaces of the base material are processed with a surface grinder, and the side surfaces of the base material are processed with a CNC grinder.
delete a) preparing a cylindrical ingot;
b) cropping the ingot to a base material of a corresponding length unit;
c) slicing the base material cropped by the corresponding length unit into a base material disc of the corresponding thickness:
d) surface processing of the base plate sliced to the corresponding thickness;
e) forming a plurality of micro-holes by electric discharge machining in which the electrode of the electric discharge machine is placed at the corresponding position on the surface-processed base plate, and then an electric discharge is generated by applying a primary power to the electrode; and
f) washing the base plate having a plurality of micro-holes formed therein;
In the step e), in the step of forming a plurality of micro-holes by electric discharge machining in which an electrode is placed at the corresponding position on the base plate with the surface processed, and then an electric discharge is generated by applying the primary power to the electrode,
Wafer etching showerhead comprising the step of locating an electrode in the center of the micro-hole formed by electric discharge machining, applying a secondary power to the electrode, and improving the surface roughness of the inner peripheral surface of the micro-hole by discharging by the secondary power manufacturing method.
5. The method according to claim 4,
The secondary power is
A method for manufacturing a wafer etching showerhead having a frequency of 1 to 10 MHz, a voltage width of 10 to 100 Vp-p, and an output current of 100 mA or less.
5. The method according to claim 4,
When improving the surface roughness of the inner peripheral surface of the microhole by discharging by the secondary power source,
The electrode is a wafer etching showerhead manufacturing method for improving the surface roughness of the inner peripheral surface of the micro-hole while axially rotating about the center.
5. The method according to claim 4,
When improving the surface roughness of the inner peripheral surface of the microhole by discharging by the secondary power source,
The electrode is a wafer etching showerhead manufacturing method for improving the surface roughness of the inner circumferential surface of the micro-hole while rotating along the inner circumferential surface of the micro-hole with the center of the micro-hole as an axis.
The method according to claim 1,
In the step f), in the step of washing the base plate having a plurality of micro-holes formed by hole processing,
and passing an abrasive through the micro-holes formed in the base plate by hydraulic pressure, and then grinding the inner peripheral surface of the micro-holes with the abrasive and post-processing the abrasive.
9. The method of claim 8,
The abrasive is
A method for manufacturing a wafer etching showerhead, characterized in that it is in the form of a gel containing silicon carbide (SiC) or diamond powder and a binder.
9. The method of claim 8,
In the step f), in the step of washing the base plate having a plurality of micro-holes formed by hole processing,
The step of immersing the base plate in a water tank containing a solvent to melt and remove the powder generated in the base plate during electric discharge machining;
The method of manufacturing a wafer etching showerhead further comprising the step of applying ultrasonic waves to a water bath containing a solvent to clean the base plate with ultrasonic waves.

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