Residual stress characterization of polycrystalline 3C-SiC films on Si(100) deposited from methylsilane

Abstract

Polycrystalline 3C-SiC thin films are deposited on 100 mm Si(100) wafers via low pressure chemical vapor deposition from the precursor methylsilane in the temperature range of 700–850 °C. Residual stress, strain, and strain gradient are characterized as functions of deposition pressure, temperature, and dichlorosilane as an additional silicon source. By optimizing the deposition parameters, the residual stress is found to decrease from 1377±10 to 196±19 MPa. The low stress film exhibits a strain of 3.4×10−4, corresponding to Young’s modulus of 455 GPa, and strain gradient of −8×10−4 μm−1. The analysis suggests that the change in stress values is due to a combination of effects, in particular, thermal mismatch, grain size effect, and chemical composition.