AJ,

I will say probably not.

By the crystalline nature of silicon, the inter-valley electron transport
mechanism that determines piezoresistive coefficients is well understood (get
Robert Keyes's age old paper) and is predictable.  Hence the numbers you quoted
do apply.

On the other hand, lattice scattering mechanisms, particularly at boundaries,
in polysilicon make piezoresistive coefficients unpredictable.  Infact, it may
vay between deposition runs.


Robert.

On Mar 15,  5:30, AJ Pang wrote:
> Subject: Re: Polysilicon - piezoresistive coefficients
> Hi MEMS,
>
> May I know will there be a big different in the Transverse and longitudinal
> piezo-resistive
> coefficient between polysilicon and silicon. If lets say I am using
> polysilicon for my sensor,
> can I use silicon as my material properity for my simulation??
>
> And :-
>
> n-type silicon:-
> resistivity  = 11.7 (ohm cm)
> p11           = -102.2
> p12           = 53.4
> p44           = -13.6
>
>
> P-type silicon:-
> resistivity = 7.8 (ohm cm)
> p11          = 6.6
> p12          =-1.1
> p44          = +138.1
>
>
> Best regard
>
> AJ Pang
>
>
>
>
>
>
> -----Original Message-----
> From: fabounp@yahoo.com 
> To: MEMS@ISI.EDU 
> Date: 15 March 1999 04:16
> Subject: Polysilicon - piezoresistive coefficients
>
>
> >I'm looking for the transverse and the longitudinal piezoresistive
> >coefficients in the case using polysilicon thin film .... Thanks ...
> >
> >
> >
> >
> >_________________________________________________________
> >DO YOU YAHOO!?
> >Get your free @yahoo.com address at http://mail.yahoo.com
> >
> >
> >
>
>
>-- End of excerpt from AJ Pang



--
Robert S. Okojie, Ph.D.
Senior Engineer
Ford Microelectronics
9965 Federal Drive, Colorado Springs, CO 80921-3698
Phone:(719)528-7727; Fax: (719)528-7529
"The frontier of knowledge has no boundary.  Paradigms rise and fall"