United Microelectronics Corp.

Chi-Sheng Chen

Shin-Chi Chen

Chih-Yueh Li

Ted Ming-Lang Guo

Tsung-Hsun Tsai

Bo-Syuan Lee

Yu-Chin Cheng

A method for removing silicon nitride material includes following steps. A substrate having at least a gate structure formed thereon is provided, and at least a silicon nitride hard mask is formed on top of the gate structure. A first removal is performed to remove a portion of the silicon nitride hard mask with a first phosphoric acid (HPO) solution. A second removal is subsequently performed to remove remnant silicon nitride hard mask with a second phosphoric acid solution. The first removal and the second removal are performed in-situ. A temperature of the second phosphoric acid solution is lower than a temperature of the first phosphoric acid solution.

Growing community of inventors

Taipei, Taiwan

Chi-Sheng Chen