CMOS N P Twin Tub Well Formation

2,869 views
2,344 views

Published on

Quick way to see how the cmos well formation occurs. Videos might not work properly! Apologies!

Published in: Engineering, Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
2,869
On SlideShare
0
From Embeds
0
Number of Embeds
8
Actions
Shares
0
Downloads
52
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

CMOS N P Twin Tub Well Formation

  1. 1. CMOS WELL FORMATION AZMATH MOOSA M. TECH 1ST YEAR DEPARTMENT OF ELECTRONICS ENGINEERING SCHOOL OF ENGINEERING AND TECHNOLOGY
  2. 2. INTRODUCTION • Well refers to a region within a p or n type substrate of opposite dopant type
  3. 3. N WELL FORMATION
  4. 4. P WELL FORMATION
  5. 5. TWIN TUB FORMATION • Provide separate optimization of the n-type and p-type transistors • Makes it possible to optimize "Vt", "Body effect", and the "Gain" of n, p devices, independently.
  6. 6. TWIN TUB • Steps: • Start with lightly doped n or p type material • "epitaxial" or "epi" layer to prevent "latch up" • Process sequence • a. Tub formation • b. Thin-Oxide construction • c. Source & drain implantations • d. Contact cut definition • e. Metallization
  7. 7. Concentrated PHOSPHOROUS AmbientConcentrated BORON Ambient TWIN TUB FORMATION N+ substrate Epitaxial Layer Photoresist Mask Photoresist P - well N - well Mask Oxide Oxide
  8. 8. THANK YOU

×