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INTRODUCTION TO SEMICONDUCTOR TECHNOLOGY

Wafer is diffused with N-type dopants to form the

source and drain junction. The transistor gate

material acts as a barrier to the dopant providing

an undiffused channel self-aligned to the two junc-

tions. The wafer is then oxidized to seal the junc-

A thick glass layer is then deposited over the wafer

(to provide better insulation), patterned with con-

tact holes and placed in a high temperature fur-

nace. Metal is deposited on the wafer and the in-

terconnect patterns and external bonding pads are

defined and etched. To prevent the device from

contamination or moisture attack, wafers are

sealed with a passivation layer. Patterning is

done for the last time opening up windows only

over the bond pads where external connections

will be made.

This completes basic fabrication sequence for a

single poly and single metal layer process.