# US 5,705,081 A · Etching method

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- Number: US 5,705,081 A
- Document ID: US5705081A
- Status: Granted
- Kind: A
- Application number: 08/531,713
- Filed: 1995-09-21
- Granted: 1998-01-06
- Earliest claimed: 1994-09-22
- Assignees: Tokyo Electron Limited
- Inventors: Koichiro Inazawa; Shin Okamoto; Yoshifumi Tahara
- Web page: https://patentgrep.com/patent/US5705081A

## CPC

- H10P 50/283: {by chemical means}
- H10P 50/242: {of Group IV materials}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

An etching apparatus comprises a pair of electrodes provided to face each other in a processing vessel, a permanent magnet for forming a magnetic field substantially parallel to a surface of a to-be-processed object which is placed between the paired electrodes, a gas introduction section for introducing etching gas into the processing vessel, a high-frequency generator for applying high-frequency voltage to the paired electrodes for generating plasma, and a high-frequency control section for preventing plasma from being unevenly distributed by starting and stopping the application of high-frequency voltage by the high-frequency generator at fixed intervals.

## Claims

### Claim 1

An etching method, comprising the steps of:
forming a magnetic field parallel to a surface of a to-be-processed object, which is placed in a processing vessel, and introducing etching gas into the processing vessel; and
applying high-frequency voltage for generating plasma between a pair of electrodes, which are provided to face each other in the processing vessel, and stopping application of the high-frequency voltage to the electrode at fixed intervals, to thereby decrease electrons in the plasma over the surface of the to-be-processed object, thereby uniformly plasma-etching the to-be-processed object.

### Claim 2 (depends on 1)

An etching method according to claim 1, wherein voltage-application time is set at not more than several hundredths of a second.

### Claim 3 (depends on 1)

An etching method according to claim 1, wherein voltage-application stop time is set at a period shorter than a life of electrons in plasma.

### Claim 4 (depends on 3)

An etching method according to claim 3, wherein the voltage-application stop time is set at not more than several hundredths of a second.

### Claim 5 (depends on 1)

An etching method according to claim 1, further comprising a step of introducing etching gas into the processing vessel and exhausting etching gas in the processing vessel, to thereby control etching gas amounts in the processing vessel.

### Claim 6 (depends on 1)

An etching method according to claim 1, wherein voltage-application stop time is set at a period shorter than a life time of electrons in plasma.

### Claim 7

An etching method, comprising the steps of:
forming a magnetic field parallel to a surface of a to-be-processed object which is placed between a pair of electrodes to face each other in a processing vessel;
introducing etching gas into the processing vessel; and
applying high-frequency voltage between the electrodes for generating plasma therebetween, stopping application of the high-frequency voltage between the electrodes at intervals, the high-frequency application time being shorter than a time in which ExB drift phenomenon becomes conspicuous, and the high-frequency application stop time being shorter than a time in which plasma disappears, to thereby decrease uneven distribution of electrons in plasma over the surface of the to-be-processed object, thereby evenly plasma-etching the to-be-processed object.