Highly crystalline silicon carbide thin films grown at low substrate temperature by HWCVD technique

Abstract

Highly crystalline cubic Silicon carbide (3C-SiC) thin films were deposited on quartz and silicon substrate at low substrate temperature of 400 °C by hot wire chemical vapour deposition technique using Silane, methane and hydrogen gases. The influence of methane flow rate (MFR) on structural and electrical properties of films has been investigated. All the deposited films are highly crystalline with crystallite size as high as 27 nm for film deposited with MFR = 6 SCCM. A decrease in crystallite size is observed with increase in MFR. Electrical conductivity of films deposited at low MFR (6–12 SCCM) is ~1 Ω−1 cm−1, however an order of decrease in conductivity has been observed as MFR increases beyond 12 SCCM. Activation energy of films also decreases monotonically with increasing MFR. The variation in dark conductivity and activation energy could be attributed to the microstructural changes in films with increasing MFR. No trace of any contamination of filament material is observed in these films. These highly crystalline and conductive films find applications in various microelectronic and optoelectronic devices.