Method for fabricating semiconductor transistor
AssigneeDongbu HiTek Co., Ltd.
InventorJeong-Yel Jang
Life of this patent
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Abstract
A method for fabricating a semiconductor transistor which eliminates device defects generated during an etching process for forming gates. The method may include laminating an ONO layer on and/or over a semiconductor substrate, and then coating a polysilicon layer on and/or over the ONO layer, and then forming a photoresist pattern on and/or over the polysilicon layer, and then sequentially performing a first etching of the polysilicon layer using the photoresist pattern as an etching mask so as to maintain a predetermined thickness of the polysilicon layer and then a second etching to remove the polysilicon layer remaining from the first etching.
Claims18
A method for fabricating a semiconductor transistor comprising:
- sequentially forming a first oxide layer, a nitride layer, and a second oxide layer as an oxide-nitride-oxide (ONO) layer on a semiconductor substrate;
- forming a polysilicon layer on the ONO layer;
- forming a photoresist pattern on the polysilicon layer;
- performing a first etching of the polysilicon layer to a predetermined thickness at a first pressure using the photoresist pattern as an etching mask;
- and then
- performing a second etching at a second pressure to remove the polysilicon layer remaining after the first etchings,
- wherein the second pressure is greater than the first pressure, and the second pressure is maintained during the second etching.
A method for fabricating a flash cell device comprising:
- forming a polysilicon layer on a semiconductor substrate;
- and then
- sequentially performing a main etching of the polysilicon layer to a predetermined thickness at a first pressure and then an over etching of the polysilicon layer at a second pressure to remove remaining portions of the polysilicon layer,
- wherein the second pressure is greater than the first pressure, and the second pressure is maintained during the over etching.
Dependencies are inferred from the claim text.