Growth and effect of deposition pressure on microstructure and electrical properties of 3C-SiC thin films deposited using methyltrichlorosilane single precursor

Abstract

This paper presents effect of deposition pressure on the microstructure and electrical properties of 3C-SiC (111) thin films. These films are deposited at a temperature of 1040 � C and pressures of 1.5, 1.8, 2.5 and 2.7 mbar, on thermally oxidized Si (100) substrates from a mixture of methyltrichlorosilane and hydrogen gas using a vertical hot wall, low pressure chemical vapour deposition (LPCVD) reactor. The above properties are investigated for all films using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and four probe technique. An FTIR spectrum shows the formation of Si-C bonding of deposited films. The SEM and XRD investigations show improvement in the grain size and crystallanity, decrease in strain and dislocations of the films with increas e in the deposition pressure from 1.5 to 2.5 mbar. AFM investigations show decrease in roughness of the films with increase in the deposi tion pressure from 1.55 to 2.5 mbar. The sheet resistance of 3C-SiC thin films is found to decrease with increase in temperature in the range of 35 to 550 � C. Comparing all the films, 3C-SiC thin films deposited at a pressure of 2.5 mbar and temperature of 1040 � C exhibited improved structural and electrical properties.