Silicon Properties

TylerJames

So I'm doing research with MEMs so we're going to be making silicon wafers that will have little cantilever beams on them which will act as an accelerometer. I need to design it so the beams break at certain forces but to do that I need the yield strength of silicon (that is the correct property isn't it?) and I can't find it anywhere. I'm thinking maybe pure silicon is not the material thats used in MEMs so if someone could point me in the direction to where I could find those mechanical properties that'd be awesome! Thanks

Tyler

phyzguy

Here's a good source:

http://parts.jpl.nasa.gov/docs/JPL%20PUB%2099-1D.pdf

Mapes

Silicon doesn't yield; it's brittle, so it fractures. And just like any brittle material, its tensile strength is very sensitive to surface properties and defects. That's why you'll probably find a large range of reported values for tensile strength, and why you'll probably be disappointed if you expect your structures to break reliably at a certain load every time.

You might find Cook's "Strength and sharp contact fracture of silicon," J Mater Sci 41 (2006) to be useful.