Preparation And Properties Of SiCN Thin Films Deposited By Reactive Magnetron Sputtering

As one of ternary compound semiconductor materials,silicon carbonitride(SiCN)has both the outstanding properties of SiC and Si3N4 in optical,electrical,magnetric,thermodynamics and mechanical.SiCN also have pontential economic and social effects due to its low-cost growth and excellent compatibility with very-large-scale integrated circuit.In this article,we have deposited ternary SiCN thin films by radio frequency magnetron sputtering method using raw silicon nitride and graphite as targets,respectively,with argon flowing.Through changing reaction parameters such as target power,substrate temperature and chamber pressure,we have investigated the composition,microstructure,morphology,optical and field emission(FE)properties of as-prepared samples systematacially.The annealing effects of SiCN thin films are also been studied exploringly.Results show that,there are three main elements Si,N and C in the obtained SiCN thin films and combined as Si-N,Si-C,C-N,C=N,C=N and C=C bonding states.Meanwhile,two crystalline phases Si3N4 and 5H-SiC were found in all the films.However,as the deposition condition changing,composition and microstructure of films have great difference.In addition,we found the optical bandgap of SiCN films increase with the Si3N4 and graphite target power increasing.The results indicates the obtained SiCN thin films have intensive transmittance.Corresponding optical bandgap could be varied from 4.55 to 4.89 eV based on Tauc function.We found the optical bandgap reduced from 4.20 to 3.73 eV with increasing the temperature of substrate.In contrast,optical bandgap grows from 3.06 to 5.14 eV with decreasing chamber pressure.By analysising the photoluminescence spectra,two peaks were found.The peaks are regarded as SiOx/Si(0<x?2)bound state and SiC crystal grain.FE properties indicate that a big variety appeared in field emission threashold electric field due to the adjustment of targets power.The smallest threashold electric field is 2.4 V/?m.