| 摘要 |
PURPOSE: A gate formation method of an SRAM(Static Random Access Memory) is provided to prevent attacks of boron and fluorine ions by using a WNx film as a diffusion barrier. CONSTITUTION: A gate oxide(2) and an undoped amorphous silicon layer(3) are sequentially formed on a silicon substrate. After sequentially implanting N-type and P-type ions into the undoped amorphous silicon layer(3), a tungsten film is deposited on the resultant structure. A WNx film(6) as a diffusion barrier and a silicon-nitrogen bonding layer are formed by implanting nitrogen ions and performing RTA(Rapid Thermal Annealing). Then, a tungsten gate(7) is formed on the resultant structure. After sequentially patterning the tungsten gate, the WNx film, the undoped amorphous silicon layer and the gate oxide, a nitride spacer(10) is formed at both sidewalls of the patterns.
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