KR20020025278A - A plasma etching apparatus - Google Patents

Abstract

PURPOSE: A plasma etching equipment is provided to reduce a damage of a wafer by minimizing a pressure difference between a reaction chamber and a transfer chamber. CONSTITUTION: A reaction chamber(100) has an RF power(110), a matching portion(120), and a multitude of gas supply hole(130) for supplying a reaction gas. A vacuum pump, a throttle valve(140), and a gate valve are installed at one side of the reaction chamber(100) in order to form vacuum of the reaction chamber(100). A transfer rod(210) is installed in a lower portion of a transfer chamber(200). A cathode electrode plate(220) for loading a wafer(400) is installed on an upper portion of the transfer rod(210). A plurality of interconnection hole(150,250) is installed in an intermediate position of a contact portion between the reaction chamber(100) and the transfer chamber(200). An interconnection tube(500) is installed between the reaction chamber(100) and the transfer chamber(200).

Description

Plasma Etching Equipment

The present invention relates to a plasma etching apparatus, and more particularly, a plasma which communicates with an action chamber in which an etching action occurs and the wear chamber and prevents an increase in pressure in a transfer chamber provided for mounting and transporting a wafer. It relates to an etching apparatus.

In general, the etching technology used in the manufacturing process of the semiconductor device is classified into wet and dry according to the etching method required.

Among them, dry etching is called plasma etching because the reaction is usually performed in a plasma state. The apparatus used for plasma etching includes a transfer chamber for transferring a wafer and a reaction chamber in communication with the transfer chamber. There is a double chamber structure.

The conventional plasma etching apparatus of the dual chamber type has a reaction chamber 10 and a reaction chamber 20 for transferring the wafer 40 to the reaction chamber 10 and the reaction chamber 10, which are greatly reacted as shown in FIG. 1. (10) is implemented as a vacuum pump 30 to make the interior a vacuum state.

In the reaction chamber 10, a high frequency power source 11 for supplying high frequency power to the reaction chamber 10, a matcher 12, and a reaction gas supply hole 13 through which a reaction gas is supplied are implemented, and a vacuum pump 30 is provided. In operation, a throttle valve 14 and a gate valve (not shown) for pumping air inside the reaction chamber 10 are installed.

The transfer chamber 20 includes a transfer rod 21 and an unshown entry and exit device for entering and exiting the cathode electrode plate 22 and the wafer 40 installed at the upper end of the transfer rod 21 into the transfer chamber 20. Is provided. Then, a high frequency power source 23 and a matching unit 24 for supplying high frequency power to the cathode electrode plate 22 are provided, respectively.

In the conventional plasma etching apparatus, the cathode electrode plate 22 on which the wafer 40 is seated is lifted by the lifting of the transfer rod 21 during its operation, and the reaction gas is supplied after being placed under the reaction chamber 10. The plasma is generated in the reaction chamber 10 by the high frequency power supplied to the reaction chamber 10 and the cathode electrode plate 22 while the vacuum pump 30 is operated, and the reaction gas ionized by the plasma Thin film etching is performed on the wafer 40.

However, the inside of the transfer chamber 20 during the operation of the etching apparatus will be preferably in a completely closed state. However, this is not a complete seal of the device's continued operation. Therefore, the external fine gas and the like flows into the transfer chamber 20 through the leaking portion during the operation, thereby partially increasing the internal pressure of the transfer chamber 20.

And when the operation of the device is completed, the cathode electrode plate 22 is moved downward along the transfer rod 21, wherein the reaction chamber 10 is in the low pressure state of the vacuum pump 30, the transfer chamber 20 When the inside is in a high pressure state and the reaction chamber 10 and the transfer chamber 20 are in instant communication, a sudden vortex inside the transfer chamber 20 due to the pressure difference between the transfer chamber 20 and the reaction chamber 10. Due to this vortex, ions, fine gases, dust particles, and the like remaining in the transfer chamber 20 adhere to the surface of the wafer 40, thereby causing a problem of damaging the surface of the wafer 40.

The present invention is to solve the above-mentioned problems, an object of the present invention is to perform a predetermined pumping operation in the transfer chamber during the vacuum pumping of the reaction chamber to minimize the pressure difference between the reaction chamber and the transfer chamber It is to provide a plasma etching apparatus which can prevent the wafer surface from being damaged by stabilizing the atmospheric pressure inside the transfer chamber.

1 is a configuration diagram schematically showing a conventional plasma etching apparatus.

2 is a schematic diagram illustrating a plasma visual apparatus according to the present invention.

3 is an enlarged cross-sectional view of part A of FIG. 2 and illustrates an installation state of a communication tube installed in the plasma etching apparatus.

Figure 4 is a partial cutaway perspective view showing a check valve installed state installed in the communication tube of the plasma etching apparatus according to the present invention.

** Description of the symbols for the main parts of the drawings **

100 ... reaction chamber

200 ... Transfer Chamber

300 ... vacuum pump

400 ... wafer

500 ... Communication tube

520 ... check valve

In order to achieve the above object, the present invention has a reaction chamber for performing a thin film etching on the wafer by a plasma reaction, a communication chamber communicating with the reaction chamber, the transfer chamber is carried out the transfer and transfer of the wafer, the reaction chamber A vacuum pump that makes the interior a vacuum state, a transfer rod operatively installed inside the transfer chamber to transfer the wafer into the reaction chamber through the wafer through the communication port, and pumping of the reaction chamber by the vacuum pump And a communication tube configured to communicate the transfer chamber and the reaction chamber with each other to lower the pressure inside the transfer chamber.

In addition, a check valve is installed in the communication tube to allow air in the transfer chamber to flow into the reaction chamber, and prevents air in the reaction chamber from flowing into the transfer chamber. An inner diameter of the communication tube is 15 mm or more and 30 mm. It is characterized by the following size.

Hereinafter, one preferred embodiment of the plasma etching apparatus according to the present invention will be described in more detail with reference to the drawings.

In the plasma etching apparatus according to the present invention, as shown in FIG. 2, the transfer chamber 200 for transferring the wafer 400 into the reaction chamber 100 and the reaction chamber 100 in which the etching action is performed on the wafer and the reaction are performed. It is implemented as a vacuum pump 300 to make the interior of the chamber 100 in a vacuum state.

First, the reaction chamber 100 is a 12.56MHz, 0-2000 watts high frequency power supply 110, a matcher 120 and a plurality of gas supply holes 130 to supply the high frequency power to the reaction chamber 100. It is provided on a wall. One side of the reaction chamber 100 is provided with a vacuum pump 300 for making the inside of the reaction chamber 100 into a vacuum state, and the air inside the reaction chamber 100 is opened when the vacuum pump 300 is operated. A throttle valve 140 and a gate valve not shown are installed to allow the furnace to be pumped.

Although not shown, the transfer chamber 200 includes an unshown power unit installed below the transfer chamber 200 and a transfer rod 210 which is lifted up and down by the power unit, and a wafer on the transfer rod 210. The cathode electrode plate 220 on which the 400 is seated is installed.

In addition, the cathode electrode plate 220 is provided with a power supply 230 and a matching unit 240 supplied with a high frequency of 13.56 MHz, 0-200 watts. In addition, an entrance / exit device (not shown) may be implemented at the side of the transfer chamber 200 to allow the wafer 400 to enter and exit the transfer chamber 200.

On the other hand, the reaction chamber 100 and the transfer chamber 200 of the plasma etching apparatus of the present invention is formed so that the communication holes 150, 250 are formed in the middle portion in contact with each other, the communication port 150 The cathode electrode plate 220 is attached to and detached from the communicating portion 250 by moving up and down.

In addition, when the cathode electrode plate 220 is raised and positioned inside the reaction chamber 100 together with the wafer 400, the communication chambers 150 and 250 are connected to each other. It is configured to seal.

In addition, between the reaction chamber 100 and the transfer chamber 200, the transfer chamber 200 and the reaction chamber at the time of pumping the reaction chamber 100 by the vacuum pump 300 separately from the communication ports 150 and 250. Communicating 100 to each other is provided with a communication tube 500 to perform some pumping, such as the reaction chamber 100 with the transfer chamber 200 also.

One end of the communicating tube 500 is coupled with the reaction chamber 100, the other end is coupled with the transfer chamber 200, and it may be appropriate to be provided with a flexible bellows tube. And the communicating tube 500 may be directly coupled to the transfer chamber 200, but may be detachably coupled to the slow vacuum line (not shown) installed on one side of the reaction chamber (100). In this case, when the end cap is installed in the opening portion of the slow vacuum line or the reaction chamber 100, the communication tube 500 is not coupled to seal the outside.

And as shown in Figures 3 and 4 in the coupling portion of the communication tube 500 and the transfer chamber 200 is provided with a connecting tube 510 for coupling the communication tube 500 and the transfer chamber 200, the communication tube ( Between the 500 and the connection pipe 510 to allow the air in the transfer chamber 200 to be distributed into the reaction chamber 100 to prevent the air in the reaction chamber 100 from flowing into the transfer chamber 200. Check valve 520 is installed.

The check valve 520 is provided in a cylindrical shape and forms a jaw portion therein, and the valve body 521 has a plurality of locking ribs 522 and the pin 524 is caught by the jaw portion inside the valve body 521. The drive plate 523 is coupled to the drive plate 523 to rotate when the flow of air is made from the transfer chamber 200 to the reaction chamber 200. When the air flows in the opposite direction, the drive plate 523 is rotated. The locking rib 522 is configured to block the flow path.

Accordingly, when the vacuum pumping action in the reaction chamber 100 is performed, the reaction chamber 100 and the transfer chamber 200 communicate with each other so that the pumping in the transfer chamber 200 is performed together, and when no vacuum pumping occurs. It is to seal between the transfer chamber 200 and the reaction chamber 100 to each other.

On the other hand, the inner diameter (D) of the communication tube 500 is preferably provided with a size of 15mm or more and 30mm or less, and most preferably it will be appropriately implemented in a size of about 25mm. If it is smaller than 15 mm, its effect will be reduced. If it is larger than 30 mm, installation will not be appropriate. This size may vary depending on the overall structure and assembly of the plasma etching apparatus itself.

Hereinafter, an operation state of the plasma etching apparatus according to the present invention configured as described above will be described.

First, the wafer 400 is transported by an entrance and exit device not shown in the transfer chamber 200 to be seated on the cathode electrode plate 220, and when the wafer 400 is seated on the cathode electrode plate 220, the transfer rod 210. As a result of the rise of the cathode electrode plate 220, the wafer 400 seated on the cathode electrode plate 220 is positioned inside the reaction chamber 200.

And the etching operation is a significant size between the RF power supplied to the reaction chamber 200 and the RF electrode supplied to the cathode electrode plate 220 at this time, if RF power is supplied to the reaction chamber 200 and the cathode electrode plate 220 The potential difference of is generated. In such a state, when an inert gas is supplied into the reaction chamber 100 through the supply hole 130 through a gas supply device (not shown), ionization of the inert gas proceeds with the potential difference inside the reaction chamber 100, Positive charges and electrons, ie, the plasma gas layer and electrons, are generated.

In addition, the plasma gas layer reacts with the exposed portion of the oxide film of the wafer 400 without being covered by the photoresist film so that the by-products are etched while the byproduct is generated.

In this etching state, the reaction chamber 100 is continuously pumped by the vacuum pump 300, and at the same time, the transfer chamber 200 is connected to the reaction chamber 100 through a communication tube 500. Pumping is performed together.

At this time, the pumping of the communication tube 500 causes the check valve 520 to rotate as the pressure inside the reaction chamber 100 decreases to open the inside of the communication tube 500 so that the air inside the transfer chamber 200 is pumped.

Therefore, such a pumping operation prevents the pressure inside the transfer chamber 200 from rising, and at the same time maintains a state similar to the pressure inside the reaction chamber 100.

When the thin film etching of the wafer 400 is completed by the continuous etching, the cathode electrode plate 220 installed in the transfer chamber 200 is lowered to be positioned in the transfer chamber 200. At this time, the reaction chamber 100 and the transfer chamber 200 are in communication with each other and the internal air flows between each other.

However, unlike the related art, since the pressure difference between the reaction chamber 100 and the transfer chamber 200 is almost uniform to each other, atmospheric instability such as vortex due to the pressure difference between the respective chambers 100 and 200 occurs. I never do that.

Therefore, the air inside the transfer chamber 200 is maintained in a stable state, and at the same time, foreign substances such as dust remaining in the transfer chamber 200 are seated on the surface of the wafer 400 or remain inside the transfer chamber 200. Damage to the surface of the wafer 200 may be minimized by a minute amount of gas or the like.

The plasma etching apparatus according to the present invention as described above is implemented so that the reaction chamber and the transfer chamber communicate with each other to solve the air instability caused by vortex due to the pressure difference between the chambers during the communication of each chamber, the etching surface is performed There is an effect that can be prevented from damaging the surface of the wafer to be seated on the fine particles and the like.

Claims (3)

Reaction chamber to perform thin film etching on the wafer by the plasma reaction, A transfer chamber having a communication port in communication with the reaction chamber, in which the wafer is fed in and out; A vacuum pump for making the inside of the reaction chamber into a vacuum state, A transfer rod operatively installed in the transfer chamber so that the wafer is positioned inside the reaction chamber through the wafer through the communication port; And a communication tube configured to communicate the transfer chamber and the reaction chamber with each other when the reaction chamber is pumped by the vacuum pump to lower the pressure inside the transfer chamber. The plasma tube of claim 1, wherein a check valve is installed in the communication tube to allow air in the transfer chamber to flow into the reaction chamber and to prevent air in the reaction chamber from flowing into the transfer chamber. Etching device. The plasma etching apparatus according to any one of claims 1 to 2, wherein an inner diameter of the communicating tube is provided in a size of 15 mm or more and 30 mm or less.