Electrical and Mechanical Characterization of Doped and Annealed Polycrystalline 3C-SiC Thin Films

Abstract

+Deposition of doped polycrystalline 3C-SiC thin films from the precursors 1,3-disilabutane (DSB) and dichlorosilane (DCS), and the dopant precursor ammonia is investigated in a large-scale low-pressure chemical vapor deposition (LPCVD) reactor for micro- and nanoelectromechanical systems (M/NEMS) applications. Films deposited from only DSB and have residual stresses in excess of tensile and resistivity values of . Addition of DCS yields films that exhibit mechanical and electrical properties more favorable for M/NEMS devices. For films deposited with DCS, electrical resistivity varies between for undoped, as-deposited films to for films doped with nitrogen. Residual stress of films deposited from DSB, DCS, and varies little for as-deposited films with different doping concentrations; however, annealing in an argon ambient shifts residual stress toward, and in some cases, into the compressive regime. The strain gradient, which is less than in magnitude for all as-deposited films from DSB, DCS, and , shifts to large negative values in excess of upon annealing for at in an argon ambient. Two sources of stress shift with annealing are identified, namely oxygen diffusion and a change in N atom bonding.