METHODS AND DEVICES EMPLOYING METAL LAYERS IN GATES TO INTRODUCE CHANNEL STRAIN

摘要

A semiconductor device (100) is fabricated having a metal stress inducing layer that facilitates channel mobility. A gate dielectric layer is formed over a semiconductor substrate (102). The metal stress inducing layer is formed over the gate dielectric layer (108). The metal stress inducing layer has a selected conductivity type and is formed and composed to yield a select stress amount and type. A gate layer, such as a polysilicon layer (114), is formed over the metal stress inducing layer. The gate layer and the metal stress inducing layer are patterned to define gate structures.