US 6,320,154 B1 · Plasma processing method

Abstract

An objective of this invention is to provide a plasma processing method that is capable of reducing particle contamination during plasma processing performed upon a semiconductor wafer. If the use of electron cyclotron resonance to generate a plasma and form a thin film of SiOF or the like is used by way of example, a sheath zone of a few mm thick is formed between the wafer and the plasma, and particles are trapped within a boundary zone between the sheath zone and the plasma. At this point, a microwave power is not dropped suddenly to zero after the film-formation processing, but is reduced to a lower level of, for example, 1 kW and is held for 10 seconds. This reduces the plasma density and thickens the sheath zone, so that particles are held away from the wafer surface. When the microwave power is subsequently cut, the particles move freely around, but only a small proportion thereof adhere to the wafer.

Claims5

Dependent claims

A plasma processing method comprising the steps of:

supplying at least electrical power to a processing gas within a processing chamber to form a plasma, and using said plasma to perform a plasma process on an object to be processed;
subsequently forming a plasma that does not promote processing at an electrical power that is lower than that used during said previous step, instead of said plasma of said processing gas, to form a sheath zone above said object to be processed that is thicker than a sheath zone thereabove during said previous step;
and
conveying said object to be processed out of said processing chamber.

1 more element

Dependencies are inferred from the claim text.

Plasma processing method

Life of this patent

Plasma processing method

Life of this patent

Abstract

Claims5