Plasma etching method
First Claim
1. A plasma etching method comprising:
- placing a sample on a sample stage arranged in a processing chamber;
supplying a processing gas toward a center of the sample from a shower plate associated with an electrode arranged in opposed relation to the sample stage, the shower plate having processing gas supply holes and being provided to a lower surface of the electrode which is closest to the sample stage;
generating plasma in the processing chamber;
applying RF power between the sample stage and the electrode for providing energy enabling charged particles in the plasma to enter the sample;
neutralizing errant charged particles which enter the processing gas supply holes from the plasma during a period of RF power, by bombardment of the errant charged particles against an inner surface of the processing gas supply holes, the errant charged particles being other than the charged particles that have entered the sample; and
etching the sample using the plasma.
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Accused Products
Abstract
A plasma etching method and apparatus in which a processing gas is supplied from a shower plate arranged on an electrode opposed to an electrode for generating a plasma or a sample toward the sample center, and the gas is transformed into a plasma thereby to etch the sample. RF power is applied between a sample stage and the electrode to apply the energy to charged particles in the plasma to thereby etch the sample. In the process, apart from the incidence of the charged particles to the sample, the charged particles enter also the shower plate of the electrode by application of the RF power. The charged particles entering the processing gas supply holes of the shower plate are neutralized to prevent abnormal discharge on the shower plate and consequently suppress the generation of foreign matter.
11 Citations
14 Claims
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1. A plasma etching method comprising:
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placing a sample on a sample stage arranged in a processing chamber;
supplying a processing gas toward a center of the sample from a shower plate associated with an electrode arranged in opposed relation to the sample stage, the shower plate having processing gas supply holes and being provided to a lower surface of the electrode which is closest to the sample stage;
generating plasma in the processing chamber;
applying RF power between the sample stage and the electrode for providing energy enabling charged particles in the plasma to enter the sample;
neutralizing errant charged particles which enter the processing gas supply holes from the plasma during a period of RF power, by bombardment of the errant charged particles against an inner surface of the processing gas supply holes, the errant charged particles being other than the charged particles that have entered the sample; and
etching the sample using the plasma. - View Dependent Claims (2, 3, 6, 7, 8)
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4. A plasma etching method for generating plasma in a processing chamber and etching a sample using the plasma, comprising:
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supplying a processing gas from a gas chamber formed between an electrode being in opposed relation to the sample, and a shower plate which is arranged in a surface of the electrode closest to a sample stage;
maintaining a processing pressure in the processing chamber at not higher than 10 Pa;
generating a plasma in a processing space formed between the sample and the electrode by a plasma generating means;
neutralizing errant charged particles attempting to enter from the plasma to the gas chamber formed between the electrode and the shower plate, by causing the errant charged particles to be impinged upon an inner surface of gas supply holes of the shower plate; and
etching the sample using the charged particles entering the sample from the plasma. - View Dependent Claims (9, 10, 11)
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5. A plasma etching method for etching a sample under a processing pressure of not higher than 10 Pa, wherein a processing gas is supplied from a position not less than 30 mm and not more than one half of a diameter of the sample in distance from the sample, toward a center of the sample through processing gas supply holes having an inclination angle (θ
- ) to a surface of the sample, smaller than tan−
1(t/d), where t is a thickness of a shower plate, and d is a diameter of a processing gas supply hole. - View Dependent Claims (12, 13, 14)
- ) to a surface of the sample, smaller than tan−
Specification