Characterization of the mechanisms producing bending moments in polysilicon micro-cantilever beams by interferometric deflection measurements

Polysilicon micro-cantilever beams and doubly-supported beams are fabricated and conditioned with phosphorus doping and high-temperature anneal cycles to assess the effects of process history and geometry on polysilicon microstructure rigidity. Using a Linnik interferometer, deflection trends for series of beams are measured and compared for several process conditions. Two bending moments can induce beam deflection: the first due to the beam boundary support, and the second due to stress nonuniformity through the beam thickness. A comparison of polysilicon microstructure deflection behavior for doping and annealing conditions is presented and discussed.<
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