Method for etching high-k metal gate stack
AssigneeSK hynix Inc.
InventorsSu-Bum Shin, Hae-Jung Lee
Life of this patent
Estimating the term…
Abstract
A method for etching a gate includes forming a high-k material layer over a substrate; forming an overlying layer over the high-k material layer; performing a first etching process for etching the overlying layer to form an overlying layer pattern; forming a spacer on a sidewall of the overlying layer pattern; and performing a second etching process using plasma including a etch gas and an additive gas, to etch the high-k material layer, wherein an amount of the additive gas is substantially the same as the main etch gas to increase an etch selectivity with respect to the substrate.
Claims19
A method for forming a gate, the method comprising:
- forming a high-k material layer over a substrate;
- forming an overlying layer over the high-k material layer;
- performing a first etching process for etching the overlying layer to form an overlying layer pattern;
- forming a spacer on a sidewall of the overlying layer pattern;
- and
- performing a second etching process using plasma including a etch gas and an additive gas, to etch the high-k material layer,
- wherein an amount of the additive gas is substantially the same as the main etch gas to increase an etch selectivity with respect to the substrate,
- wherein the second etching process is performed at a temperature higher than the first etching process.
Dependencies are inferred from the claim text.