Study of indium diffusion throughpolycrystalline silicon and silicon dioxide

• Main Authors: HSIN-JEN WANG, 王興仁
• Other Authors: RUEY-DAR CHANG
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/98793178031026402251

碩士 === 長庚大學 === 電子工程研究所 === 94 === As semiconductor technology is scaling down to deep sub-micron, it becomes increasingly difficult to control the leakage current of transistors. Indium gives a steeper profile to suppress short channel effects of metal oxide semiconductor transistors (MOSFET). Extensive experiments have been performed. Samples were implanted in either silicon or polycrystalline silicon (poly-Si) to investigate indium diffusion through oxide. Samples were implanted with at a dose of 1x1014 atoms/cm2 at 150keV, the annealing temperature ranges from 750℃ to 900℃. We used secondary ion mass spectrometry (SIMS) for profile measurement and process simulation for extracting diffusion coefficients. It is found that the segregation effect of indium from poly-Si into oxide is not strong. Similar segregation behavior was found between silicon and oxide. Enhanced diffusion of indium was found in oxide after poly-Si deposition. We believe that oxide film may trap hydrogen atoms from SiH4 during poly-Si deposition to affect indium diffusion. It is also found that indium diffusion in poly-Si from silicon through a thin oxide is larger than that from a thick oxide. This implies that the hydrogen trapping in oxide might decrease the indium diffusion in poly-Si. The studies create a new diffusion model for indium in oxide and poly-Si. In the future, the modeling result can be used for advanced device technology.