Plasma etching method and apparatus therefor
AssigneeTokyo Electron Limited
InventorKoji Maruyama
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Abstract
A fluorine-containing compound gas, e.g., SF6 gas, is converted into a plasma and a silicon portion of an object to be processed is etched by the plasma. At the same time, using a light source having a peak intensity of light in a wavelength range of light absorption of a reaction product, e.g., SiF4, for which, to be more precise, ranges from 9 μm to 10 μm, the light is irradiated onto a surface of an object to be processed from the light source. The SiF4 molecules absorb the light, become activated and gain kinetic energy to be used in gaining an easy escape from a hole. As a consequence, an amount (a partial pressure) of fluorine radicals (F*) used as an etchant is increased and an etching rate of a silicon is increased.
Claims11
A plasma etching method, comprising the steps of:
- converting a process gas including a fluorine-containing compound gas into a plasma;
- and
- etching a silicon portion of an object to be processed with the plasma,
- wherein a light having a peak intensity of light in a wavelength range of light absorption of a reaction product produced by an etching is irradiated onto a surface of the object to be processed.
A plasma etching apparatus for etching a silicon portion of an object to be processed mounted on a susceptor with a plasma which is obtained by converting a process gas including a fluorine-containing compound gas thereinto in an airtight process chamber, the apparatus comprising:
- a light source which emits a light having peak intensity of light in a wavelength range of light absorption of a reaction product between the fluorine-containing compound and silicon, and irradiates the light onto a surface of the object to be processed mounted on the susceptor;
- and
- a gas supply unit introducing the process gas into the process chamber.
Dependencies are inferred from the claim text.