Method for providing short channel effect control using a silicide VSS line
View Patent ↗A method for fabricating a semiconductor device having improved short channel effects is disclosed. The method includes operations such as, forming a hard mask layer on the surface of a semiconductor substrate, printing a photoresist mask above the hard mask layer, performing an etch of trenches in the semiconductor substrate and removing the hard mask layer and the photoresist mask. Moreover, the method includes forming a first polysilicon layer, etching the first polysilicon layer, forming a spacer layer and forming a second polysilicon layer. In addition, the method includes performing a stacked gate etch on the second polysilicon layer, performing an SAS etch, performing a shallow source implant and forming the spacer between the first polysilicon layer and the second polysilicon layer. A silicide line is subsequently formed to connect device source regions.
1. A semiconductor device comprising:
a semiconductor substrate;
a first polysilicon layer formed above said semiconductor substrate;
a second polysilicon layer formed above said first polysilicon layer and above said semiconductor substrate;
a spacer layer situated between said first polysilicon layer and said second polysilicon layer and above said semiconductor substrate;
source implants formed in said semiconductor substrate wherein said source implants are disposed as shallow implants in said substrate; and
a silicide line connecting source regions of said semiconductor device.
2. The semiconductor device of claim 1 further comprising a stacked gate arrangement.
3. The semiconductor device of claim 2 wherein the effective channel length of said semiconductor device is increased in relation to a decrease in the lateral diffusion of a source junction.
4. The semiconductor device of claim 3 wherein said spacer prevents shorting of said first polysilicon layer and said second polysilicon layer.
5. The semiconductor device of claim 4 wherein said silicide line comprises CoSi.
6. The semiconductor device of claim 5 wherein the resistance of the silicide line is 100 times less than the resistance of doped silicon.
7. The semiconductor device of claim 6 wherein said spacer layer comprises an ONO layer.