Semiconductor device and forming method

Abstract

The invention provides a semiconductor device and a forming method. A dielectric layer of a semiconductor device may be treated using an oxidation treatment process to adjust a dielectric constant of the dielectric layer. For example, an etch stop layer (ESL) in an interconnect layer of a semiconductor device may be formed of a high dielectric constant (high k) dielectric material that provides etch selectivity to the ESL relative to other dielectric layers in the interconnect layer. A recess may be formed through the ESL and through the dielectric layer, and a conductive structure may be formed in the recess. Before forming the conductive structure, an oxidation treatment operation may be performed to oxidize an exposed end of the ESL in the recess. The oxidation treatment can reduce the dielectric constant of the end portion of the ESL, which can make the end portion of the ESL less susceptible to current leakage caused by tunneling effect, hot carrier injection and / or hot electron emission.

Images