Method for etching inside of tungsten CVD reaction room
AssigneeNEC Corporation
InventorTakao Akiyama
Life of this patent
Estimating the term…
Abstract
Disclosed is a method for etching the inside of a tungsten CVD reaction room, in which tungsten deposited on the inside of the reaction room by a film-forming gas when a tungsten CVD reaction is conducted is removed by plasma, and which has the steps of: exhausting a remainder of the film-forming gas in the reaction room; and then supplying a high-frequency electric power into the reaction room while keeping a predetermined degree of vacuum in the reaction room and leading a mixing gas of sulfur hexafluoride and oxygen into the reaction room to generate the plasma.
Claims3
A method for etching the inside of a tungsten CVD reaction room, in which tungsten deposited on the inside of said reaction room by a film-forming gas when a tungsten CVD reaction is conducted is removed by plasma, comprising the steps of:
- exhausting a remainder of said film-forming gas in said reaction room;
- leading a first mixing gas of sulfur hexafluoride and oxygen into said reaction room to generate a first vacuum degree;
- supplying a first high-frequency electric power into said reaction room to generate said plasma cooperatively with said first mixing gas;
- leading a second mixing gas of sulfur hexafluoride and oxygen into said reaction room to generate a second vacuum degree which is different from said first vacuum degree;
- and
- supplying a second high-frequency electric power into said reaction room to generate said plasma cooperatively with said second mixing gas.
Dependencies are inferred from the claim text.