Integrated circuit fabrication dual plasma process with separate introduction of different gases into gas flow

• US 20020179248A1
• Filed: 08/01/2002
• Published: 12/05/2002
• Est. Priority Date: 12/22/2000
• Status: Active Grant

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: Alex Kabansky
• Inventors: Kabansky, Alex
• Granted Patent: US 6,641,698 B2
• Time in Patent Office: Days
• US Class Current: 156/345.36
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01L 21/31138 by dry-etching

Abstract

A dual plasma process generates a microwave neutral plasma remote from a semiconductor wafer and a radio frequency (RF) ionized plasma adjacent to the wafer for simultaneous application to the wafer. A first gas flows through a microwave plasma generation area, without a second gas in the gas flow, to generate the neutral microwave plasma. The second gas is added to the gas flow downstream of the microwave plasma generation area prior to an RF plasma generation area.

Claims

1. A dual plasma process assembly in which a semiconductor wafer is subjected to a dual plasma process in which first and second plasmas are formed from gases in first and second plasma generation areas, respectively, and applied simultaneously to the semiconductor wafer, the gases include first and second gases, comprising:

a gas flow path from the first plasma generation area, through the second plasma generation area and to the semiconductor wafer, the first plasma generation area being upstream of the second plasma generation area in the gas flow path; and

a gas mixture area in the gas flow path between the first and second plasma generation areas, downstream of the first plasma generation area and upstream of the second plasma generation area; and

wherein;

the first gas enters the gas flow path at the first plasma generation area and flows through the gas mixture area and the second plasma generation area to the semiconductor wafer; and

the second gas enters the gas flow path at the gas mixture area downstream of the first plasma generation area, mixes with the first plasma in the gas mixture area and flows through the second plasma generation area to the semiconductor wafer.

2. A dual plasma process assembly as defined in claim 1 wherein the dual plasma process is an etch and clean process.

3. A dual plasma process assembly as defined in claim 1 further comprising:

a plurality of distribution nozzles disposed between the first and second plasma generation areas; and

wherein;

the gas mixture area is upstream of the distribution nozzles.

4. A dual plasma process assembly as defined in claim 1 further comprising:

a plurality of distribution nozzles disposed between the first and second plasma generation areas; and

wherein;

the gas mixture area is downstream of the distribution nozzles.

5. A dual plasma process assembly as defined in claim 4 for connecting to a source for the second gas, wherein:

a first portion of the distribution nozzles connects to the first plasma generation area;

a second portion of the distribution nozzles connects to the source for the second gas;

the first plasma flows through the first portion of the distribution nozzles;

the second gas flows through the second portion of the distribution nozzles; and

the second gas and the first plasma mix together upon exiting from the distribution nozzles.

6. A dual plasma process assembly as defined in claim 1 further comprising:

a microwave energy source proximate to the first plasma generation area that delivers microwave energy to the first plasma generation area;

and wherein the first plasma is generated from the first gas and the microwave energy in the first plasma generation area.

7. A dual plasma process assembly as defined in claim 6 wherein the gas mixture area is remote from the microwave energy source.

8. A dual plasma process assembly as defined in claim 7 further comprising:

a radio frequency energy source proximate to the second plasma generation area that delivers radio frequency energy to the second plasma generation area;

and wherein the second plasma is generated from a gas mixture of the first gas containing the first plasma and the second gas and the radio frequency energy in the second plasma generation area.

9. A dual plasma process assembly as defined in claim 1 wherein the first gas includes a non-fluorine gas.

10. A dual plasma process assembly as defined in claim 9 wherein the non-fluorine gas is selected from the group consisting of oxygen, nitrogen, argon, carbon monoxide and water.

11. A dual plasma process assembly as defined in claim 1 wherein the second gas is a fluorine gas.

12. A dual plasma process assembly as defined in claim 11 wherein the fluorine gas is selected from the group consisting of carbon tetrafluoride, fluoroform, hexafluoroethane, nitrogen trifluoride and sulfur hexafluoride.