KR100562994B1 - Apparatus for processing substrate with plasma - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for generating a plasma in a vacuum chamber to perform a predetermined process on a substrate.

The present invention provides a plasma processing apparatus for generating a plasma in a vacuum chamber to perform a predetermined treatment on a substrate, the plasma processing apparatus comprising: an upper electrode and a lower electrode respectively provided at upper and lower portions of the chamber to apply high frequency power into the chamber; A shower head coupled to an upper electrode rim protruding downward from the upper electrode, and diffusing a process gas into the chamber; An exhaust unit disposed between the lower electrode and the side wall of the chamber, and configured to suck the gas inside the chamber and discharge the gas to the outside; And a gas flow control unit protruding downward from the chamber at the edge of the shower head and adjusting a flow direction and speed of the process gas diffused to the edge of the shower head. to provide.

Plasma Processing Equipment, Shower Head, Plasma, Uniformity, Gas Flow Control

Description

Plasma Processing Equipment {APPARATUS FOR PROCESSING SUBSTRATE WITH PLASMA}

1 is a cross-sectional view illustrating the structure of a conventional plasma processing apparatus.

2 is a view showing a process gas flow in a conventional plasma processing apparatus.

3 is a cross-sectional view illustrating a structure of a plasma processing apparatus according to an embodiment of the present invention.

4 is a partial perspective view illustrating a structure of a shower head and a gas flow adjusting unit according to an embodiment of the present invention.

5 is a view showing a horizontal movement of the gas flow control unit according to an embodiment of the present invention.

6 is a front view of a gas flow adjusting unit according to an embodiment of the present invention.

7 is a view showing the structure of the gas flow adjusting unit and the stopper according to another embodiment of the present invention.

8 is a view showing the structure of the gas flow control unit according to another embodiment of the present invention.

9 is a view showing a process gas flow in the plasma processing apparatus according to an embodiment of the present invention.

<Description of Symbols for Major Parts of Drawings>

1: conventional plasma processing apparatus

100: plasma processing apparatus according to an embodiment of the present invention

10, 110: upper electrode 12, 112: shower head

20, 120: lower electrode 30, 130: internal lifting pin

40, 140: exhaust 150: gas flow control unit

152: rotating part 154: stopper

G: gate valve C: chamber

S: Substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for generating a plasma in a vacuum chamber to perform a predetermined process on a substrate.

BACKGROUND OF THE INVENTION Many plasma processing apparatuses for treating a surface of a substrate using plasma have been used in manufacturing processes such as semiconductor devices and liquid crystal display devices. Examples of such a plasma processing apparatus include a plasma etching apparatus for etching a substrate, a plasma CVD apparatus for performing chemical vapor deposition (CVD), and the like.

As shown in FIG. 1, the plasma processing apparatus 1 includes two flat plate electrodes 10 and 20 that face each other in parallel with each other. The substrate S is mounted on the lower electrode 20 of the two electrodes. Therefore, this lower electrode 20 is also called a substrate mounting table.

In addition, as shown in FIG. 1, the plasma processing apparatus 1 is provided with an internal elevating pin 30 and an external elevating bar to assist a process of carrying in or carrying out a substrate into the processing apparatus. At this time, the internal elevating pin 30 is formed through the edge of the lower electrode 20, passes through the through-hole 22 formed in the lower electrode 20 is driven up and down.

And an external lifting bar (not shown) is provided separately on the outside of the lower electrode 20. That is, it is provided in a space formed between the side wall of the lower electrode 20 and the side wall of the plasma processing apparatus, and has a structure capable of driving up and down. In some cases, this external lifting bar may not be installed.

Next, the upper electrode 10 is provided at a position facing the lower electrode 20. This upper electrode not only serves as an electrode, but also serves as a process gas supply unit for supplying process gas between both electrodes. Accordingly, as shown in FIG. 1, a shower head 12 is coupled to the lower portion of the upper electrode 10. Here, the shower head 12 is formed with a plurality of process gas diffusion holes 14 having fine diameters. Therefore, the process gas is uniformly supplied to the space between the both electrodes 10 and 20 through the shower head 12. The processing gas supplied between the electrodes becomes a plasma by application of high frequency power to the electrodes, and the surface of the substrate is processed by the plasma.

The plasma processing apparatus 1 is provided with an exhaust section 40 for exhausting the gas therein. The exhaust unit 40 sucks and removes gas in the plasma processing apparatus 1 by a pump (not shown) provided outside the plasma processing apparatus 1, and maintains the interior of the plasma processing apparatus in a vacuum state. do. In general, the exhaust part 40 is disposed in the space between the lower electrode 20 and the side wall of the chamber C, in particular at the corner side of the lower electrode 20.

In the plasma processing apparatus 1, as described above, the processing gas supplied from the upper electrode 10 moves in a plasma state by an electric field formed by both electrodes to process the substrate S. However, as described above, since the exhaust part 40 is disposed at the edge of the chamber C to suck the gas in the chamber C, in a portion close to the exhaust part 40, as shown in FIG. 2. As a result, the gas flow is much faster than the central part of the chamber. When the gas flow is changed in this way, there is a problem in that the uniformity of the substrate becomes difficult because the degree of processing of the substrate is changed. This problem is getting worse as the substrate becomes larger.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma processing apparatus for improving the uniformity of substrate processing by making the gas flow constant in all regions inside the chamber.

In order to achieve the above object, the present invention, in the plasma processing apparatus for generating a plasma in the chamber in a vacuum to perform a predetermined process, the upper and lower chambers respectively provided for applying high frequency power to the chamber An upper electrode and a lower electrode; A shower head coupled to an upper electrode rim protruding downward from the upper electrode, and diffusing a process gas into the chamber; An exhaust unit disposed between the lower electrode and the side wall of the chamber, and configured to suck the gas inside the chamber and discharge the gas to the outside; And a gas flow control unit protruding downward from the chamber at the edge of the shower head and adjusting a flow direction and speed of the process gas diffused to the edge of the shower head. to provide.

In the present invention, the gas flow adjusting unit is coupled to the rim of the shower head by the rotating unit, and the gas flow adjusting unit rotates around the rotating unit to adjust the angle, thereby providing a gas flow rate according to the process diagram. It is desirable to make it possible to adjust.

In the present invention, it is preferable that the rotating part further includes a horizontal moving part for horizontally moving the rotating part in a direction parallel to the lower surface of the shower head so that the injection direction and the flow rate of the process gas can be adjusted appropriately.

At this time, in the present invention, it is preferable that the gas flow control unit is arranged over all parts of the edge of the shower head, so that the gas flow is constant over all parts on the lower electrode.

In the present invention, it is preferable that the gas flow adjusting unit is divided into four parts so as to correspond to each side of the shower head so as to be driven respectively, so that angle adjustment or horizontal movement of the gas flow adjusting unit is facilitated.

At this time, it is preferable that each gas flow adjusting unit has an equilateral trapezoidal shape having a length lower than that of the upper end, so that the gas flow adjusting unit does not interfere with each other while rotating about the rotational unit.

In the present invention, it is preferable that the gas flow adjusting unit is made of a ceramic material so as not to be damaged by plasma or to generate particles during the process.

In addition, in the plasma processing apparatus according to the present invention, a stopper is provided inside the lower edge of the showerhead and protrudes downward so that the gas flow control unit stops without turning over a certain angle when the gas flow control unit is rotated. It is desirable to prevent excessive rotation of the gas flow control unit and to prevent damage to the shower head or the like.

Hereinafter, with reference to the accompanying drawings will be described in detail a specific embodiment of the present invention.

Plasma processing apparatus 100 according to the present embodiment, as shown in Figure 3, the chamber (C); Upper electrode 110; Lower electrode 120; Showerhead 112; An exhaust unit 140; It is configured to include a gas flow control unit (150).

In this case, the chamber C, the upper electrode 110, the lower electrode 120, the shower head 112, the exhaust 140 has the same structure and function as that of the conventional plasma processing apparatus 1, so Do not repeat.

Hereinafter, the configuration and operation of the gas flow control unit 150 which is a characteristic part of the plasma processing apparatus 100 according to the present embodiment will be described. As shown in FIG. 3, the gas flow adjusting unit 150 protrudes below the chamber C at the edge of the shower head 112 and is diffused to the edge of the shower head 112. It is a component that controls the flow direction and velocity of gas. The gas flow adjusting unit 150 is formed in a thin plate shape, and prevents the process gas ejected from the shower head 112 from flowing rapidly in the direction of the exhaust unit 140 so that the gas flow is at the edge of the lower electrode 120. Prevents it from getting faster.

In this embodiment, the gas flow adjusting unit 150 is disposed over all parts of the edge of the shower head 112, as shown in FIG. This is to ensure that all parts on the substrate S are treated uniformly, and when the gas flow adjusting unit 150 is not disposed at a particular part, the gas flow in the part may be faster and the uniformity of the process may be worsened. Because there is.

At this time, the gas flow adjusting unit 150, as shown in Figure 4, is preferably provided in four divided pieces. That is, it is divided into four to correspond to each side of the shower head (112). This is to facilitate the rotational drive and horizontal movement of each gas flow control unit 150. When the entire gas flow adjusting unit is formed of one member, the angle adjustment is difficult, and the horizontal position movement is also difficult. Therefore, it is divided into four to facilitate the angle and position movement, and each divided gas flow control unit to be driven separately.

At this time, each gas flow control unit 150, as shown in Figure 6, it is preferable that the length of the lower end is shorter is trapezoidal shape than the length of the upper end. In the case where the trapezoid is formed in an isosceles trapezoidal shape, the gas flow control unit 150 does not interfere with each other even if the angle formed by the shower head 112 is small.

In this embodiment, as shown in FIG. 3, the gas flow adjusting unit 150 is coupled to the shower head 112 using the rotating unit 152. Therefore, the gas flow adjusting unit 150 is rotatable about the rotating unit 152. The reason for rotating the gas flow adjusting unit 150 is to control the gas flow freely according to the degree of process, since the gas flow direction and speed vary according to the arrangement angle of the gas flow adjusting unit 150. That is, when the gas flow rate of the substrate edge portion is larger than the center portion, the gas flow adjusting unit 150 reduces the angle formed by the showerhead 112 surface to further reduce the gas flow rate, and in the opposite case, increases the angle by increasing the gas. It will increase the flow rate.

In addition, in this embodiment, a horizontal moving part (not shown in figure) is further provided in this rotating part 152. As shown in FIG. The horizontal moving part is provided in combination with the rotating part 152 and horizontally rotates the rotating part 152 and the gas flow adjusting part 150 in a direction parallel to the lower surface of the shower head 112 as shown in FIG. 5. Move it. The horizontal movement of the gas flow control unit 150 is to enable fine adjustment of the gas flow direction and speed according to the degree of process processing. That is, when the gas flow cannot be adjusted as desired by only adjusting the angle of the gas flow adjusting unit 150, the gas flow is controlled by moving the position of the gas flow adjusting unit 150 using the horizontal moving unit. Therefore, the gas flow is more effectively controlled by using two points, an angle adjustment and a horizontal position adjustment.

In addition, the gas flow adjusting unit 150 according to the present embodiment is preferably formed of a ceramic material. Since the gas flow control unit is disposed in the space where the plasma is generated, the material is preferably made of ceramic because the material must be a plasma resistant material resistant to the plasma. Therefore, the gas flow controller 150 according to the present exemplary embodiment has an advantage in that arcing phenomenon or particles do not occur during substrate processing.

In addition, in the plasma processing apparatus 100 according to the present exemplary embodiment, as shown in FIG. 7, the shower head 112 is provided at an inner side of the rim, and protrudes downward to rotate the gas flow at the time of rotation of the gas flow adjusting unit 150. It is preferable that a stopper 154 is further provided to stop the adjustment unit without turning over a predetermined angle, since the rotational movement of the gas flow control unit 150 can be easily controlled.

In addition, as shown in FIG. 8, a plurality of gas flow adjusting units may be disposed. That is, the plurality of gas flow adjusting units 150a, 150b, 150c, and 150d are disposed to be spaced apart at predetermined intervals in parallel to each side of the shower head 112. And each gas flow control unit (150a, 150b, 150c, 150d) is provided in a structure that can be independently driven rotation and horizontal movement. When a plurality of gas flow adjusting units are provided as described above, the gas flow control unit can precisely cope with the difference in the minute gas flow from the central region of the shower head 112 to the edge region, thereby obtaining a more constant gas flow. At this time, the plurality of gas flow control unit (150a, 150b, 150c, 150d), as shown in Figure 8, the length thereof is preferably shortened toward the central portion of the shower head (112). This is to correspond to the gas flow faster toward the edge of the shower head 112.

According to the present invention, since the direction and speed of the process gas flow ejected from the shower head can be finely controlled, there is an advantage of eliminating the process nonuniformity due to the difference in gas flow in each region of the substrate.

That is, as shown in FIG. 8, the process gas ejected from the shower head 112 does not flow in the direction of the exhaust unit 140, but its direction and speed are changed by the gas flow adjusting unit 150 so that the substrate The flow is similar to the central part of. Therefore, the processing degree of the center area | region and the edge area | region of a board | substrate becomes uniform.

Claims (9)

A plasma processing apparatus for generating a plasma in a chamber in a vacuum state to perform a predetermined treatment on a substrate. An upper electrode and a lower electrode provided at upper and lower portions of the chamber to apply high frequency power to the inside of the chamber; A shower head coupled to an upper electrode rim protruding downward from the upper electrode, and diffusing a process gas into the chamber; An exhaust unit disposed between the lower electrode and the side wall of the chamber, and configured to suck the gas inside the chamber and discharge the gas to the outside; It is provided to protrude to the lower side of the chamber portion of the shower head, the gas flow control unit for adjusting the flow direction and speed of the process gas diffused to the edge of the shower head; The gas flow adjusting unit, Is coupled to the rim portion of the shower head by a rotating portion, and rotates around the rotating portion is provided with a plasma processing apparatus characterized in that the angle can be adjusted. delete The method of claim 1, wherein the rotating part, And a horizontal moving part configured to horizontally move the rotating part in a direction parallel to a lower surface of the shower head. According to claim 3, wherein the gas flow control unit, Plasma processing apparatus characterized in that it is disposed over all parts of the edge of the showerhead. The method of claim 4, wherein the gas flow control unit, Plasma processing apparatus characterized in that the four divided to correspond to each side of the shower head is provided to be driven. According to claim 5, The gas flow control unit, Plasma processing apparatus, characterized in that the length of the lower end is an equilateral trapezoidal shape shorter than the length of the upper end. The method of claim 3, A plurality of gas flow control unit is disposed so as to be spaced apart a predetermined interval parallel to each side of the shower head, The plurality of gas flow control unit is provided with a plasma processing apparatus, characterized in that the rotational drive and the horizontal movement is provided independently. The gas flow adjusting unit of claim 1 or 3, wherein the gas flow adjusting unit includes: Plasma processing apparatus, characterized in that formed of a ceramic material. The method of claim 8, Plasma processing apparatus is provided on the inside of the lower edge of the shower head, the stopper protruding downward to stop the gas flow control unit does not rotate more than a predetermined angle during rotation of the gas flow control unit is further provided. .

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