Direct comparison of stiction properties of oxide coated polysilicon and smooth single crystal silicon

We directly compare both the process and in-use stiction properties of two identical sets of devices fabricated with both rough oxide-coated polysilicon and smooth, oxide-free single crystal silicon. The polysilicon devices show dramatically reduced process stiction as a result of the surface roughness, enabling higher yield on more compliant structures. In-use stiction is slightly higher for the polysilicon-oxide devices than it is for the single crystal devices. Our ultra-high purity, vacuum encapsulation process allows careful measurement of surface adhesion properties in the absence of environmental variation.