LOCOS with Sacrificial Poly-Silicon

 
Here is a comparison of the LOCOS process with and without some sacrificial poly-Si:
LOCOS with sacrificial poly-Si layer
Provided, some of the oxide is removed by an "etch-back" process, the lateral extension can be kept somewhat smaller than in the conventional case.
While this makes things quite complicated, the final versions of the LOCOS process were even more complicated.

With frame With frame as PDF

go to 6.2.2 LOCOS Process

© H. Föll (Electronic Materials - Script)