Young's Modulus and Fracture Strength of Three Polysilicons

Abstract

ABSTRACTPolysilicon specimens from Cronos, Sandia, and Standard MEMS, Inc. were tested in tension. The specimens were nominally 6 or 20 μm wide and 250 or 1000 μm long. The Cronos and the Standard MEMS specimens had thicknesses of 1.5, 2.0, and 3.5 μm; whereas, the Sandia specimens were all 2.5 μm thick.There was no dramatic difference in Young's modulus for the three materials. A total of 117 tests were run, and the average modulus for all three materials was 157 ± 9 GPa. However, the strengths were quite different: 1.56 ± 0.25 GPa for the Cronos material, 2.85 ± 0.40 GPa for Sandia's, and 2.04 ± 0.30 GPa for the SMI polysilicon.