Patent ID: 8283242

Claim:
A method, comprising: forming a photoresist pattern over a certain portions of a material layer to expose an ion implantation region; implanting impurities in the ion implantation region of the material layer using the photoresist pattern as an ion implantation barrier; and removing the photoresist pattern using plasma of a gas mixture including diimide (N 2 H 2 ), the removing the photoresist pattern comprising: performing a first step at a first temperature using plasma of N 2 H 2 and oxygen (O 2 ), wherein a ratio of the N 2 H 2 to the O 2 ranges approximately 4-6:1; performing a second step, using plasma of N 2 H 2 and O 2 , at a second temperature higher than the first temperature; and performing a third step using plasma of N 2 H 2 alone.