US Patent 11264478 Transistors with reduced defect and methods forming same

A device includes a semiconductor region, an interfacial layer over the semiconductor region, the interfacial layer including a semiconductor oxide, a high-k dielectric layer over the interfacial layer, and an intermixing layer over the high-k dielectric layer. The intermixing layer includes oxygen, a metal in the high-k dielectric layer, and an additional metal. A work-function layer is over the intermixing layer. A filling-metal region is over the work-function layer.