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0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 Expose photoresist through n-well mask
Strip off exposed photoresist Lithography Strip Photoresist
Strip off remaining photoresist
Use mixture of acids called piranah etch Necessary so resist doesn’t melt in next step SiO2 000000000000 000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
p substrate ECEN 475 71.4 n-well
n-well is formed with diffusion or ion implantation
Place wafer in furnace with arsenic gas
Heat until As atoms diffuse into exposed Si Ion Implanatation
Blast wafer with beam of As ions
Ions blocked by SiO2, only enter exposed Si SiO2 0000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
n well 81.4 ECEN 475 9 Strip Oxide
Strip off the remaining oxide using HF
Back to bare wafer with n-well
Subsequent steps involve simi...
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This document was uploaded on 03/02/2014.
- Spring '09
- Integrated Circuit