Method of making a MOS field effect transistor in an integrated circuit

摘要

A method for making a MOS field effect transistor structure having tungsten silicide contact surfaces for the gate and source and drain regions is disclosed. Protective oxide is very precisely positioned so that a tungsten layer is formed on only selected silicon surfaces by selective deposition. Next, a layer of polysilicon is formed on said tungsten layer. The resulting structure is treated in an oxygen atmosphere to form the desired tungsten silicide. A silicon nitride cap can also be used to cover the gate portion during source and drain formation.