Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Are MultiVT Filler cells only NWell or complete MOS devices?

Status
Not open for further replies.

design_oriented

Advanced Member level 4
Joined
Jan 21, 2010
Messages
103
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,298
Activity points
1,991
Hi Guys,

Are multi Vth FILLER cells only Nwell implants or are they full PMOS devices with VDD and VSS taps? As threshold voltage gets mentioned, I assume they have a gate and diffusion regions.

If they are just Nwell implants on P substrate i.e. diodes, what is meant by threshold voltage?

Thanks.
 

yadavvlsi

Advanced Member level 3
Joined
Nov 19, 2010
Messages
978
Helped
485
Reputation
968
Reaction score
454
Trophy points
1,343
Location
Bangalore, India
Activity points
6,990
Filler cells are only N-well implants. They are used for N-well continuity. Now a day you have multi-Vt libraries. Variation in threshold voltage is obtained by varying channel dopping. So for each Vt an additional fabrication mask is required. Different Vt have their own well continuity as they have different dopping levels and masks. So you have different fillers cells for different VT. Filler doesn't have any threshold voltage.
 

ramkka

Junior Member level 3
Joined
Mar 31, 2008
Messages
25
Helped
4
Reputation
8
Reaction score
4
Trophy points
1,283
Activity points
1,399
Hi yadavvlsi,
thanks for an answer.

Jack
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top