Stress control of polycrystalline 3C-SiC films in a large-scale LPCVD reactor using 1,3-disilabutane and dichlorosilane as precursors

Control of residual stress and strain gradient of polycrystalline SiC films deposited via low-pressure chemical vapor deposition on 100 mm Si wafers is achieved by varying dichlorosilane (DCS) and 1,3-disilabutane (DSB) fractions in the inlet gas mixture. For films deposited at 800 degrees C and 45 sccm DSB, stress decreases from 1.2 GPa tensile with no added DCS to 240 MPa tensile with 40 sccm DCS added to the inlet gas stream. The lowest magnitude strain gradient achieved is 3.1 x 10(-5) mu m(-1) with 20 sccm DCS added. Electron probe microanalysis indicates that the films change from being slightly carbon-rich in the absence of DCS to successively more silicon-rich with the addition of DCS.