Method of hard mask CD control by Ar sputtering
AssigneeLam Research Corporation
InventorsWonchul Lee, Qian Fu
Life of this patent
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Abstract
A method for etching features into a silicon based etch layer through a patterned hard mask in a plasma processing chamber is provided. A silicon sputtering is provided to sputter silicon from the silicon based etch layer onto sidewalls of the patterned hard mask to form sidewalls on the patterned hard mask. The etch layer is etched through the patterned hard mask.
Claims19
A method for etching features into a silicon based etch layer through a patterned hard mask in a plasma processing chamber, comprising:
- providing a silicon sputtering to sputter silicon from the silicon based etch layer onto sidewalls of the patterned hard mask to form sidewalls on the patterned hard mask, wherein the silicon is sputtered primarily in the direction from the silicon based etch layer onto the sidewalls of the patterned hard mask;
- and
- etching the etch layer through the patterned hard mask.
A method for etching features into a silicon based etch layer through a patterned hard mask in a plasma processing chamber, comprising:
- providing a silicon sputtering to sputter silicon from the silicon based etch layer onto sidewalls of the patterned hard mask to form sidewalls on the patterned hard mask, wherein the silicon is sputtered primarily in the direction from the silicon based etch layer onto the sidewalls of the patterned hard mask, comprising:
- flowing a sputtering gas into the plasma processing chamber, wherein the sputtering gas comprises an argon gas and is etchant free;
- forming the sputtering gas into a plasma to generate argon ions;
- providing a bias greater than 200 volts that accelerates the argon ions in the plasma to the silicon based etch layer with sufficient energy to sputter silicon from the silicon based etch layer;
- and
- stopping the flow of the sputtering gas;
- and
- etching the etch layer through the patterned hard mask.
Dependencies are inferred from the claim text.