Claims
- 1. A method for preventing lifting of a silicide layer in a semiconductor device, the method comprising:forming a silicide layer on a first layer within a layer stack; and forming a cap layer on the silicide layer, the cap layer including nitrogen and having a concentration of nitrogen that varies as a function of a thickness of the cap layer.
- 2. The method as recited in claim 1, wherein the step of forming the cap layer includes forming a layer of silicon oxynitride on the silicide layer.
- 3. The method as recited in claim 2, wherein the step of forming the layer of silicon oxynitride on the silicide layer includes forming a first portion of silicon oxynitride wherein the concentration of nitrogen is at least about 10 atomic percent.
- 4. The method as recited in claim 3, wherein the concentration of nitrogen in the first portion of silicon oxynitride is less than about 20 atomic percent.
- 5. The method as recited in claim 3, wherein the step of forming the layer of silicon oxynitride on the silicide layer further includes forming a second portion of silicon oxynitride having a second concentration of nitrogen that is less than about 10 atomic percent.
- 6. The method as recited in claim 5, wherein the second concentration of nitrogen within the second portion of silicon oxynitride is between about 2 to about 3 atomic percent.
- 7. The method as recited in claim 1, further comprising forming the first layer by depositing a layer of polysilicon over a dielectric layer within the layer stack.
Parent Case Info
This application is a divisional of Application Ser. No. 09/134,525 filed Aug. 14, 1998.
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
07321368A |
Dec 1995 |
JP |
08097425A |
Apr 1996 |
JP |