Method for manufacturing dummy gate in gate-last process and dummy gate in gate-last process

摘要

A method for manufacturing a dummy gate in a gate-last process is provided. The method includes: providing a semiconductor substrate; growing a gate oxide layer on the semiconductor substrate; depositing bottom-layer amorphous silicon on the gate oxide layer; depositing an ONO structured hard mask on the bottom-layer amorphous silicon; depositing top-layer amorphous silicon on the ONO structured hard mask; depositing a hard mask layer on the top-layer amorphous silicon; forming photoresist lines having a width ranging from 32 nm to 45 nm on the hard mask layer; and etching the hard mask layer, the top-layer amorphous silicon, the ONO structured hard mask and the bottom-layer amorphous silicon in accordance with the photoresist lines, and removing the photoresist lines, the hard mask layer and the top-layer α-Si. Correspondingly, a dummy gate in a gate-last process is also provided.