Taiwan Semiconductor Manufacturing Comp. Ltd.

Wei-Yu Tsai

Chang-Sheng Lee

Fu-Yao Nien

Hong-Wei Huang

A semiconductor device includes a substrate, an isolation structure on the substrate, a fin protruding from the substrate and through the isolation structure, a gate stack engaging the fin, and a gate spacer on sidewalls of the gate stack. The gate spacer includes an inner sidewall facing the gate stack and an outer sidewall opposing the inner sidewall. The inner sidewall has a first height measured from a top surface of the fin and a bowed structure in a top portion of the inner sidewall. The bowed structure extends towards the gate stack for a first lateral distance measured from a middle point of the inner sidewall. The first lateral distance is less than about 8% of the first height.

Radical etching in gate formation

A method includes providing a structure having a substrate and a fin protruding from the substrate; forming a dummy gate stack over the fin; forming a gate spacer on sidewalls of the dummy gate stack; removing the dummy gate stack using a radical etch process, resulting in a gate trench; and forming a metal gate stack in the gate trench.

Growing community of inventors

Hsinchu, Taiwan

Wei-Yu Tsai