Residual Stress in CVD-grown 3C-SiC Films on Si Substrates

Abstract

Having superior mechanical properties, 3C-SiC is one of the target materials for power MEMS applications. Growing 3C-SiC films on Si is challenging, as there is a large mismatch in lattice parameter and thermal expansion between the SiC film and the Si substrate that needs to be accommodated, and results in high residual stress. Residual stress control is critical in MEMS devices as upon feature release it results in substantial deformation.3C-SiC single crystalline films were deposited on 50 mm (100) and (111) Si substrates in a hot-wall CVD reactor. The film tensile residual stress was so high that it fractured on the (111) Si wafer. The resulting film thickness on the (100) Si wafer was non-uniform, having a linear profile along the growth direction. This presented a challenge of using the substrate curvature method for calculating residual stress. Finite Element Method correction was applied to the Stoney's formula for calculating the residual stress along the wafer radius. Suggestions for reducing the amount of residual stress are made.

CBr4 as precursor for VPE growth of cubic silicon carbide

“…It is also to be considered that the samples were grown with a non rotating substrate, so a certain degree of precursor depletion, especially for SiH 4 , is expected. This lead to thickness inhomogeneity towards the wafer length, as commonly observed in experimental geometry similar to ours [26], and may be one of the causes for island nucleation and coalescence. AFM images were acquired on the same sample (Fig.…”

Fourier transform infrared spectroscopy investigation of chemical bonding in low-k a-SiC:H thin films

“…This sample consisted of a 500 nm thick 3C-SiC epilayer heteroepitaxially grown by CVD on [100] Si single-side polished 50 mm diameter substrates [38]. The materials properties established for 3C-SiC in the literature are also included in Table 1 [39][40][41].…”

Orientation-dependent stress relaxation in hetero-epitaxial 3C-SiC films

“…4,7 The limited understanding of residual stresses for 3C-SiC on Si and the presence of contradictory reports in the literature are due to the hurdles in obtaining a systematic and comprehensive stress analysis of the hetero-epitaxial films. [8][9][10] Raman spectroscopy has been the most common mean of stress analysis for 3C-SiC films, 11,12 however, the stress information from Raman is local, i.e., typically from a few lm 2 film area, and as it relates to an averaged stress for all fundamental directions. 13 A quantitative assessment of biaxial strain with Raman spectroscopy needs specific and accurately calibrated biaxial coefficients.…”