during fabrication why poly(gate) is manufacture first?

[siddharth1501]

fabrication

hi all

during fabrication why poly(gate) is manufacture first?

 

[keith1200rs]

Because it prevent diffusion unto the active area when making the source/drain.

Keith

 

[siddharth1501]

ok keith thanks alot for ur reply.may i know wat is the order of fabrication like first poly gate and next ......

 

[erikl]

may i know wat is the order of fabrication like first poly gate and next ......

Below pls. find the process flow of a 0.18µm standard CMOS process:

 

[siddharth1501]

hi erikl

i have seen ur pdf its good n useful n it also in detali.but it still not clear for me. can u refer me how can i clearly understand.

 

[erikl]

can u refer me how can i clearly understand.

You can find the details in any book about CMOS technology. See here a figure which describes the implant masking by the poly gate: It is from this Weste/Harris book: