The image illustrates the LOCOS technology used in microfabrication mostly to create isolating structures.
I. Preparation of silicon substrate
II. CVD deposition of SiO2, pad/buffer oxide
III. CVD deposition of Si3N4, nitride mask
IV. Etching of nitride layer and silicon oxide layer
V. Thermal growth of silicon oxide
VI. Furhter growth of thermal silicon oxide
VII. Removal of nitride mask
1) Si, silicon substrate
2) SiO2, pad/buffer oxide, chemical vapor deposition silicon oxide
3) Si3N4, nitride mask

4) SiO2, isolation oxide, thermal oxide
Own work
Twisp