| Summary: | 碩士 === 國立交通大學 === 材料科學與工程學系所 === 103 === Novel amorphous SiCxNy coatings are becoming increasingly attractive because of their mechanical, optical and electronic properties. Such films show promising applications for solar cells and organic light-emitting diodes (OLEDs) applications owing to their high transmittance and reduced reflection in ultra-violet and visible range as well as their excellent moisture barrier properties. In addition, SiCxNy materials can be tailored and fabricated into a wide range of band-gap for optoelectronic devices applications.
In this thesis, SiCxNy films are fabricated by radio frequency (RF) chemical vapor deposition (PECVD) using silazane single precursor at lower power density to achieve better compositional control and lower dielectric leakage. In specific, three unique single precursors: [(n-methyl-aza-2,2,4-trimethylsilacyclopentane (MTSCP), 1,3-divinyl-1,1,3,3-tetramethyl- disilazane (DVTMDS), and 1,3,5-trimethyl-1,3,5-trivinyl-cyclotrisilazane (VSZ)) of various C/Si and N/Si ratios, and with or without vinyl groups were studied. We examined the effects of the precursor chemical structure and deposition conditions such as substrate temperature on the optical properties of SiCxNy films. Compared to MTSCP, the vinyl groups of DVTMDS and VSZ readily formed the Si-(CH2)2-Si methylene bridge cross-linking in SiCxNy films, resulting in better mechanical strength, thermally stability, and optical transmittance. SiCxNy films prepared at 400 oC by using VSZ and DVTMDS possessed better optical stability and maintained at ~ 83% and ~65% transmittance in visible wavelength, respectively. In contrast, the N-CH3 and Si-CH2CH3 bondings of MTSCP could be easily broken into fragments under plasma deposition conditions, leading to less retained -CH2 or –CH3 bondings, i.e. more Si-N or Si-C bondings. When Ts was increased to 400℃, the transmittance of MTSCP thin films dropped to 50% in visible range. Nevertheless, at low deposition temperature, SiCxNy films prepared by these 3 precursors all exhibit high transmittance and high optical band gap. The chemical structures, optical band gap, and reflectance of SiCxNy films using VSZ, MTSCP, and DVTMDS were also examined and discussed in this thesis.
|
|---|
