n-Type amorphous carbon thin films prepared by radio-frequency plasma enhanced chemical vapor deposition using ammonia/ethylene mixtures

• Main Authors: Wei-Yuan Huang, 黃威遠
• Other Authors: Sham-Tsong Shiue
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/59667031760656102186

碩士 === 國立中興大學 === 材料科學與工程學系所 === 101 === The study investigates the effects of different NH3/C2H4 ratios and annealing temperatures on the properties of n-type amorphous hydrogenated carbon thin (a-C:H(N)) films deposited on p-type silicon substrate prepared by plasma enhanced vapor deposition. The plasma diagnosis, coating thickness, microstructure and optical property are analyzed using the optical emission spectrometer, field emission scanning electron microscope, raman scattering spectrometer, X-ray photoelectron spectrometer, fourier transform infrared spectroscopy and UV/Vis/IR spectrophotometer, respectively.The current-voltage curves of a-C:N/p-Si device were measured by current-voltage curve instrument. Experimental results indicate that as the NH3/C2H4 ratios increasing from 0 to 1, the deposition rate, the degree of ordering and optical band gap of carbon films decreases, while the nitrogen-carbon bonds, nitrogen/carbon ratios, sp2 carbon fraction of carbon films and forward current density of a-C:N/p-Si devices increase. The dangling bond fraction of carbon films and optical band gap decrease as the annealing temperatures increasing from 300℃ to 375℃, while sp2 carbon fraction of carbon films increase. RSS and XPS indicate that structure tends to graphite-like with increasing annealing temperature. Furthermore, when the temperature exceeds 350℃, optical band gap and sp2 carbon fraction of carbon films have obvious variations. After annealed at 325℃, there was the highest forward current density. Finally, experimental results show that as NH3/C2H4 ratio was 1 and annealing temperature was 325℃, the a-C:N/p-Si device has the highest forward current density of 9.0 mA/cm2 and the best ideality factor of 2.0.