# US 8,772,172 B2 · Semiconductor device manufacturing method and plasma etching apparatus

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- Number: US 8,772,172 B2
- Document ID: US8772172B2
- Status: Granted
- Kind: B2
- Application number: 13/947,477
- Filed: 2013-07-22
- Published: 2013-11-14
- Granted: 2014-07-08
- Earliest claimed: 2010-02-05
- Assignees: Tokyo Electron Limited
- Applicants: Tokyo Electron Limited
- Inventors: Masato Kushibiki; Eiichi Nishimura
- Web page: https://patentgrep.com/patent/US8772172B2

## CPC

- H10P 50/242: {of Group IV materials}
- H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma}
- H01J 37/32165: {Plural frequencies}
- H01J 37/3244: {Gas supply means}
- H01J 37/32449: {Gas control, e.g. control of the gas flow}
- H01J 37/32706: {Polarising the substrate}
- H10P 50/268: {of silicon-containing layers}
- H10P 50/283: {by chemical means}
- H10P 50/285: {of materials not containing Si, e.g. PZT or Al2O3}
- H10P 72/0421: {for drying etching}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

A semiconductor device manufacturing method includes a plasma etching step for etching an etching target film formed on a substrate accommodated in a processing chamber. In the plasma etching step, a processing gas including a gaseous mixture containing predetermined gases is supplied into the processing chamber, and a cycle including a first step in which a flow rate of at least one of the predetermined gases is set to a first value during a first time period and a second step in which the flow rate thereof is set to a second value that is different from the first value during a second time period is repeated consecutively at least three times without removing a plasma. The first time period and the second time period are set to about 1 to 15 seconds.

## Claims

### Claim 1

A semiconductor device manufacturing method comprising:
a plasma etching step for etching a single etching target film formed on a substrate accommodated in a processing chamber, wherein the processing chamber includes a pressure control valve,
wherein in the plasma etching step, a processing gas including a gaseous mixture containing a plurality of predetermined gases is supplied into the processing chamber, and wherein said plasma etching step includes a cycle, wherein said cycle is repeated consecutively at least three times without extinguishing a plasma generated in the processing chamber, and further wherein said cycle includes a first step in which a flow rate of at least one of the predetermined gases is set to a first value during a first time period, and said cycle further includes a second step in which the flow rate of said at least one of the predetermined gases is set to a second value that is different from the first value during a second time period;
wherein a total flow rate of the plurality of predetermined gases in the first step and a total flow rate of the plurality of predetermined gases in the second step are set to be substantially equal to each other, or a difference between the total flow rates, if there exists, is set to range within about 10% of the larger one of the total flow rates so that a pressure variation between the first step and the second step is in a range in which a pressure control valve provided in the processing chamber is operable; and
wherein a gas for facilitating etching of the etching target film is contained in the processing gas in each of the first and the second step.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first time period and the second time period are each set to range from about 2.5 to 10 seconds.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first time period and the second time period are set to be equal to each other.

### Claim 4 (depends on 1)

The method of claim 1, wherein the single etching target film is a silicon oxide film;
wherein the processing gas contains at least a fluorine compound gas; and
wherein a flow rate of the fluorine compound gas is set to the first value in the first step and to the second value in the second step.

### Claim 5 (depends on 4)

The method of claim 4, wherein the fluorine compound gas is C4F6 gas.

### Claim 6 (depends on 4)

The method of claim 4, wherein the processing gas contains O2 gas and Ar gas.

### Claim 7 (depends on 1)

The method of claim 1, wherein the single etching target film is an amorphous silicon film; the processing gas contains at least NF3 gas, HBr gas and O2 gas; and
wherein a flow rate of NF3 gas is set to the first value in the first step and to the second value in the second step.

### Claim 8 (depends on 1)

The method of claim 1, wherein the single etching target film is a carbon film;
wherein the processing gas contains at least HBr gas and O2 gas; and
wherein flow rates of HBr gas and O2 gas are set to the first value in the first step and to the second value in the second step.