Semiconductor device having metal alloy gate and method for manufacturing the same

摘要

A semiconductor device and a method for manufacturing the semiconductor device are provided. The semiconductor device uses an aluminum alloy, rather than aluminum, for a metal gate. Therefore, the surface of the high-k metal gate after the CMP is aluminum alloy rather than pure aluminum, which can greatly reduce defects, such as corrosion, pits and damage, in the metal gate and improve reliability of the semiconductor device.

主权项

1. A method for manufacturing a semiconductor device, comprising:
forming a substrate; forming an interlayer dielectric layer on the substrate and a dummy gate embedded in the interlayer dielectric layer; removing the dummy gate to form a recess in the interlayer dielectric layer; depositing a gate insulating layer having a high dielectric constant over the interlayer dielectric layer and the substrate; depositing a first barrier layer on the gate insulating layer; depositing a first metal layer on the first barrier layer; depositing a second metal layer on the first metal layer; performing annealing to melt an upper portion of the first metal layer and a lower portion of the second metal layer into an alloy; and performing chemical mechanical polishing until the interlayer dielectric layer and the alloy are exposed.