Re: Piezoresistance coefficients of polysilicon(JOJI
JOYKUTTY)

gujju

2006-01-18

>
> "RE:piezoresistance coefficients of polysilicon"
> Hi JOJI,
>
> my name is kunal.i am the new member of mems-talk.currently i am working
> in intellisuite software
> which is specificaly used for MEMS solution.i saw your query.the solution
> is given below.
>
>
> For Polysilicon, you can specify the value of Pi12 as zero
> In the Material…Define Piezoresistive Material…Change Pi12 to zero
and
> specify
> approximate values for Pi 11 and Pi44.
>
>
> Pi Longitudinal= 1/2*(pi11+pi12+pi44)
> Pi Transverse= 1/2*(pi11+pi12-pi44)
>
> in this equation you know Pi Longitudinal and Pi Transverse and you can
> use pi12 = 0.
> Thus you can solve the 2 equations to find approx. values of pi11 and
> pi44, which can be input for simulation purposes.
>
>
> N-type Poly: Plane stress dominates
>
> P-type Poly: Pi44 dominates (Shear dominates)
>
> Please let me know if this helps you.
>
> Regards
> Kunal.