Poly orientation in Matching Pattern of cmos

[smruti_s]

Why poly orientation should be same within a matching pattern.

Assume all the MOSes are seeing equal environment, but they aren't aligned i.e. their poly are kept in alternate direction(say, one horizontal & one vertical).
How is it going to affect the circuitry.

 

[Dominik Przyborowski]

The two reasons exists. First, non perpendicullar implantation produce different channel profiles for devices not placed in the same manner. Second, the silicon is an anisotropy material so it also could affect the biasing condition

 

[smruti_s]

The two reasons exists. First, non perpendicular implantation produce different channel profiles for devices not placed in the same manner. Second, the silicon is an anisotropy material so it also could affect the biasing condition

can you please elaborate.
What is meant by Channel profiles for devices???

 

[Dominik Przyborowski]

Sorry, I thought abour source/drain regions while I writed channel. Non-perpendicular implantation could shift S/D regions, change profile on the channel/source and channel/drain border and produce additional gradients of electric field, increasing hot carrier injection effects, etc.

The good explanation is given by Pelgrom in chapter 11.3 of his book "Analog to Digital conversion", from springer 2010 (in second edition of this book from 2013 it could be other chapter)