Patent ID: 11881401
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A method of forming metal features, comprising:
providing a substrate having a device formed thereon and a mask layer formed on the device, wherein the mask layer has opening patterns therein, and each of the opening patterns has a width and a length greater than the width and extending along a longitudinal direction thereof;
transferring the substrate into a process chamber;
performing a cyclic treatment process by introducing a first gas and a second gas into the process chamber alternately multiple times, so as to increase the length, from a top view, of each of the opening patterns along the longitudinal direction thereof and simultaneously push two opposite sidewalls of each of the opening patterns away from each other;
transferring the substrate out of the process chamber; and
forming metal features in the opening patterns,
wherein a cycle of the cyclic treatment process comprises:
forming a protection layer conformally on the dielectric layer, wherein the protection layer covers a sidewall and a bottom of each of the opening patterns; and
forming a directional etching process to completely remove the protection layer and simultaneously increase the length of each of the opening patterns.