Etcher for semiconductor manufacturing

Abstract

The present invention provides an etcher for semiconductor manufacturing. The etcher comprises a chamber for accepting a wafer, having an inlet and outlet through which a gas is pumped into and out of the chamber, first and second electrodes generating an electrical field to ionize the gas for reacting with the wafer, and a plate disposed between the inlet and outlet, deflecting the gas flow therebetween.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an etcher for semiconductor manufacturing, particularly to an etcher having a plate deflecting the gas flow in the chamber to eliminate teeth defects on the wafer.

[0003] 2. Description of the Prior Art

[0004] FIG. 1 is a diagram showing a conventional plasma etcher. The plasma etcher comprises a cylindrical chamber 11 having an inlet 14 and outlet 15, a positive electrode 12, and a negative electrode 13. A wafer 16 disposed on a boat 17 is accepted by the chamber 11.

[0005] The operation of the plasma etcher will be explained.

[0006] The boat 17 carrying the wafer 16 is pushed into the chamber 11. The air in the chamber 11 is then extracted to form a vacuum and a gas (a combination of oxygen and CF4 for example) for etching reaction is pumped into the chamber 11 through the inlet 14. An electrical field is generated by and between the positive and negative electrodes 12 and 13. Thus, the gas in the chamber 11 is ionized and becomes a plasma reacting with the wafer 16. The un-reacted and reacted gas are continuously pumped into and out of the chamber 11 through the inlet 14 and outlet 15 respectively to maintain a proper gas pressure and concentration during the reaction.

[0007] The arrows in the FIG. 1 show a gas flow in the chamber 11 resulting from the continuous pumping of the gas. The gas almost flows from the inlet 14 to the outlet 15 in the same direction.

[0008] However, the gas is not well distributed and does not stay too long in the chamber 11 since the gas flow is directly from the inlet 14 to the outlet 15. This results in teeth defects on the periphery of the wafer 16.

SUMMARY OF THE INVENTION

[0009] Therefore, the object of the present invention is to provide an etcher for semiconductor manufacturing, wherein the gas flow in the chamber is deflected by a plate so that the gas is well distributed and the teeth defects are prevented.

[0010] The present invention provides an etcher for semiconductor manufacturing. The etcher comprises a chamber for accepting a wafer, having an inlet and outlet through which a gas is pumped into the chamber, first and second electrodes generating an electrical field to ionize the gas for reacting with the wafer, and the reacted gas is pumped out from the chamber through the outlet, and a plate disposed between the inlet and outlet, and deflecting a gas flow therebetween. The present invention further may further provide a plurality of holes disposed in the plate, through which the reacted gas flows to the outlet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following detailed description, given by way of example and not intended to limit the invention solely to the embodiments described herein, will best be understood in conjunction with the accompanying drawings, in which:

[0012] FIG. 1 is a diagram showing a conventional plasma etcher.

[0013] FIG. 2 is a diagram showing a plasma etcher according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014] FIG. 2 is a diagram showing a plasma etcher according to one embodiment of the invention. The plasma etcher comprises a cylindrical chamber 21 having an inlet 24 and outlet 25, a positive electrode 22, a negative electrode 23, and a plate 28 having holes 281 and 282. A wafer 26 disposed on a boat 27 is accepted by the chamber 21.

[0015] The operation of the plasma etcher will be explained.

[0016] The boat 27 carrying the wafer 26 is pushed into the chamber 21. The air in the chamber 21 is then extracted to form a vacuum and a gas (a combination of oxygen and CF4 for example) for etching reaction is pumped into the chamber 21 through the inlet 24. An electrical field is generated by and between the positive and negative electrodes 22 and 23. Thus, the gas in the chamber 21 is ionized and becomes a plasma reacting with the wafer 26. The un-reacted and reacted gas are continuously pumped into and out from the chamber 21 through the inlet 24 and outlet 25 to maintain a proper gas pressure and concentration during the reaction.

[0017] The arrows in the FIG. 2 show gas flow into the chamber 11 resulting from the continuous pumping of the gas. There is turbulence in the gas flow since the gas pumped into the chamber is blocked by the plate 28. The plate 28 deflects the gas flow. This makes distributes the gas more thoroughly and keeps it longer in the chamber 21. The reacted gas then flows through the holes 281 and 282 to the outlet 25 and is pumped out from the chamber 21. Teeth defects on the periphery of the wafer 26 are thus eliminated.

[0018] In conclusion, in the invention, a plate deflects the gas flow in the chamber so that the gas is well distributed and stays longer therein, whereby teeth defects on the periphery of the wafer are prevented.

[0019] While the invention has been described by way of example and in terms of the preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

Claims

1. An etcher for semiconductor manufacturing comprising:

a chamber for accepting a wafer, having an inlet and outlet through which a gas is pumped into and out of the chamber respectively;

a first and second electrodes generating an electrical field to ionize the gas for reacting with the wafer; and

a plate disposed between the inlet and outlet, deflecting the gas flow therebetween.

2. The etcher as claimed in claim 1 wherein the chamber is a cylindrical chamber.

3. The etcher as claimed in claim 1 wherein the chamber further accepts a boat on which the wafer is disposed.

4. The etcher as claimed in claim 1 wherein the gas is a combination of oxygen and CF4.

5. The etcher as claimed in claim 1 wherein the plate is made of quartz.

6. An etcher for semiconductor manufacturing comprising:

a chamber for accepting a wafer, having an inlet and outlet through which a gas is pumped into and out of the chamber respectively;

a first and second electrodes generating an electrical field to ionize the gas for reacting with the wafer; and

a plate disposed between the inlet and outlet, deflecting the gas flow therebetween, and having a plurality of holes through which the reacted gas flows to the outlet.

7. The etcher as claimed in claim 6 wherein the chamber is a cylindrical chamber.

8. The etcher as claimed in claim 6 wherein the chamber further accepts a boat on which the wafer is disposed.

9. The etcher as claimed in claim 6 wherein the gas is a combination of oxygen and CF4.

10. The etcher as claimed in claim 6 wherein the plate is made of quartz.