METAL LAYER PROTECTION DURING WET ETCHING

• Main Authors: Yeo, Yee-Chia, Chang, Huicheng, Chen, Kuo-Ju, Liu, Su-Hao
• Format: Patent
• Language: English
• Published: 28.12.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Disclosed is a method of fabricating a contact in a semiconductor device. The method includes: receiving a semiconductor structure having an opening into which the contact is to be formed; forming a metal layer in the opening; forming a bottom anti-reflective coating (BARC) layer in the opening; performing implanting operations with a dopant on the BARC layer and the metal layer, the performing implanting operations including controlling an implant energy level and controlling an implant dosage level to form a crust layer with a desired minimum depth on top of the BARC layer; removing unwanted metal layer sections using wet etching operations, wherein the crust layer and BARC layer protect remaining metal layer sections under the BARC layer from metal loss during the wet etching operations; removing the crust layer and the BARC layer; and forming the contact in the opening over the remaining metal layer sections.