Date:          24 Jun 1996 10:53:33 -0700
From:          "Steve Bolin" 
Subject:       Need for thin film mechanical properties data
To: MEMS@ISI.EDU
Reply-to: mems@ISI.EDU


We are trying to perform mechanical modelling of MEMS devices for theorectical
reliability study.  We are currently using bulk mechanical properties of the
materials used in these devices.  (Primarily gold, platinum, nickel, silicon
and silicon nitride)  Does anyone know of published work giving the mechanical
properties of thin films of these materials?

Thanks,


Steve.Bolin@jpl.nasa.gov

________________________________________________
Steve,

The mechanical properties of these thin film materials (if available) are
scattered throughout many technical journals, conference proceedings, etc. The
best way I found to obtain available material properties is to talk with
someone who has undertaken software development for analysis MEMS components
(for example, IntelliSense Corp. has a database that is commercially available.
This is the only easily obtained database for MEMS materials of which I am
aware.).

I am interested in discussing reliability of MEMS components and what data,
etc. you think should be obtained to aid in reliability and life cycle
predictive capabilities for MEMS. Also, I think your need for mechanical
property data on MEMS materials highlights a critical need within MEMS to
develop a qualified material properties database using standardized test
methods (as an example ASTM standard methods), and utilizing test equipment
where the performance (e.g., load applied, displacement, etc.) may be verified
with acceptable standards (such as NIST standards). Another critical feature of
mechanical property testing, will be the direct measurement of the specimen
dimensions. I am unaware of any routine measurement of specimen dimensions
prior to reporting mechanical properties. I have the impression that the
specimen dimensions are estimated based upon knowledge of the processes (e.g.,
lithographic) used. Reporting of the correlation between processing-related
dimensions (such as mask feature dimensions) and actual specimen dimensions
would be useful.

Good luck obtaining the properties you need,

Howard Last
Materials Engineeer
Naval Surface Warfare Center
Indian Head Division
Indian Head, MD
4140e@uwdesign.ih.navy.mil