ETCHING METHOD FOR SUBSTRATE TO BE PROCESSED AND PLASMA-ETCHING DEVICE

• US 20150118858A1
• Filed: 04/10/2013
• Published: 04/30/2015
• Est. Priority Date: 05/08/2012
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Takaba, Hiroyuki
• Granted Patent: US 9,721,803 B2
• Time in Patent Office: Days
• US Class Current: 438/719
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32926 Software, data control or modelling
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

In one embodiment of the present invention, an etching method for a substrate to be processed comprises: (a1) a step in which etchant gas is supplied into a processing container than accommodates a substrate to be processed; (b1) a step in which the inside of the processing container is evacuated; (c1) a step in which a noble gas is supplied into the processing container; and (d1) a step in which microwaves are supplied into the processing container so as to excite the plasma of the noble gas inside the processing container. The sequential process including the step of supplying the etchant of supplying the etchant gas, the evacuating step, the step of supplying the noble gas, and the step of exciting the plasma of the noble gas may be repeated.

Claims

1. A method of etching a substrate to be processed, the method comprising:

supplying an etchant gas into a processing container that accommodates the substrate to be processed;

evacuating the inside of the processing container;

supplying a noble gas into the processing container; and

exciting plasma of the noble gas within the processing container by supplying microwaves into the processing container.

2. The method of claim 1, wherein a series of processes including the supplying of the etchant gas, the evacuating, the supplying of the noble gas, and the exciting of the plasma of the noble gas is repeated.

3. The method of claim 1, wherein the substrate to be processed includes a polycrystalline silicon layer, and the etchant gas is Cl₂ gas.

4. A plasma etching device comprising:

a processing container;

a first supply unit configured to supply an etchant gas into the processing container;

an exhaust unit configured to evacuate an inside of the processing container;

a second supply unit configured to supply a noble gas into the processing container;

a microwave supply unit configured to supply microwaves into the processing container; and

a control unit configured to control the first supply unit, the exhaust unit, the second supply unit, and the microwave supply unit to supply an etchant gas into a processing container, then to evacuate the inside of the processing container, then to supply a noble gas into the processing container, and then to supply microwaves into the processing container to excite plasma of the noble gas within the processing container.

5. The plasma etching device of claim 4, wherein the control unit controls the first supply unit, the exhaust unit, the second supply unit, and the microwave supply unit to repeat a series of processings of supplying an etchant gas into the processing container, then evacuating the inside of the processing container, then supplying the noble gas into the processing container, and then supplying microwaves into the processing container to excite the plasma of the noble gas within the processing container.

6. The plasma etching device of claim 4, wherein the first supply unit supplies Cl₂ gas as the etchant gas.

7. A method of etching a substrate to be processed, the method comprising:

supplying a noble gas into a processing container that accommodates the substrate to be processed and supplying microwaves to excite plasma; and

alternately increasing and decreasing a supply amount of the etchant gas in relation to an inside of the processing container in which the substrate to be processed is accommodated, in a period of exciting the plasma.

8. The method of claim 7, wherein in the alternately increasing and decreasing the supply amount of the etchant gas, supply of the etchant gas and supply stop of the etchant gas are alternately switched.

9. The method of claim 7, wherein the substrate to be processed includes polycrystalline silicon and silicon nitride, and the etchant gas includes CH₃F gas.

10. A plasma etching device comprising:

a processing container;

a first supply unit configured to supply an etchant gas into the processing container;

a second supply unit configured to supply a noble gas into the processing container;

a microwave supply unit configured to supply microwaves into the processing container; and

a control unit configured to control the first supply unit, the second supply unit, and the microwave supply unit to alternately increase and decrease a supply amount of the etchant gas in relation to an inside of the processing container, in a period of supplying the noble gas into the processing container and supplying the microwaves into the processing container to excite plasma.

11. The plasma etching device of claim 10, wherein the control unit alternately switches supply of the etchant gas and supply stop of the etchant gas.

12. The plasma etching device of claim 10, wherein the first supply unit supplies a gas including CH₃F gas as the etchant gas.