Patent ID: 6987061
Filing Date: 2006-01-17
Classification: H01L

Abstract:
1. A method of forming silicides on first and second transistors, where the transistors are formed upon a silicon substrate and include respective silicon gate stacks, and where the silicon gate stacks and exposed portions of the substrate are covered in a layer of oxide material and where portions of the layer of oxide material are covered by respective sidewall spacers formed adjacent the gate stacks, the method comprising: forming a layer of masking material over the second transistor; removing exposed portions of the layer of oxide material from the first transistor, thereby exposing a top portion of the silicon gate stack of the first transistor; removing the masking material from the second transistor; forming a first layer of metal material over both of the transistors; forming a first silicide on the exposed top portion of the silicon gate stack of the first transistor; removing unreacted first layer of metal material thus exposing oxide material; removing exposed oxide material from the second transistor, thereby exposing a top portion of the silicon gate stack of the second transistor; forming a second layer of metal material over both of the transistors; forming a second silicide on the exposed top portion of the silicon gate stack of the second transistor; and forming a secondary silicide on the first silicide formed on the top portion of the silicon gate stack of the first transistor.