A molecular-level investigation of the hot-wire chemical vapor deposition chemistry of si-containing thin films

点击翻译按钮获取中文摘要

Hot-wire chemical vapor deposition (HWCVD) is one of the most promising techniques for producing device-quality silicon-containing thin films needed for a wide variety of applications in solar cells, semiconductor industry and biotechnology. The proposed research program aims at providing a molecular-level understanding of the fundamental chemistry and physics in HWCVD of silicon carbide and silicon nitride alloy materials, and applying the knowledge for an optimization of film formation processes. We will use two laser-based ionization methods, i.e., vacuum ultraviolet (VUV) single-photon ionization (SPI) and laser induced electron impact ionization (LIEI), coupled with time-of-flight (TOF) mass spectrometry (MS) to identify the nature of the gas-phase film growth precursors and to determine the chemical kinetics that govern their formation. Laser spectroscopic techniques, including resonance-enhanced multiphoton ionization (REMPI) and zero kinetic energy (ZEKE) photoelectron/mass analyzed threshold ionization (MATI), will be used to characterize the structure, bonding and energetic properties of gaseous silicon carbide (SixCy) and silicon nitride (SinNm) clusters. This will help develop highly sensitive and selective diagnostic method for these reactive species and contribute to the understanding of growth mechanisms since these gaseous clusters can be viewed as prototypes for the interactions of carbon and nitrogen atoms with silicon sites at surfaces. We will also characterize the structural and compositional changes of the silicon carbide and silicon nitride thin films prepared using different source gases and various deposition parameters. The results will be correlated with those from our studies of gas-phase chemistry using laser ionization mass spectrometric and spectroscopic techniques for a complete picture of the growth processes, both in the gas-phase and on the substrate surfaces. The proposed research will provide importance guidance towards an efficient and rational optimization of film formation in HWCVD to obtain superior quality silicon-conatining thin films for industrial applications.