Summary: | 碩士 === 國立交通大學 === 電子工程系 === 89 === In this thesis, excimer laser (KrF) processes are introduced to improve the performance of TFTs. The laser crystallized poly-Si TFTs have larger grain size but rougher surface which yield more variations on device characteristics, comparing to SPC poly-Si TFTs. The performance of laser crystallized TFTs is better than that of SPC TFTs. However, the mobility of laser crystallized TFTs is similar to that of SPC TFTs , which is due to larger surface roughness in laser crystallization in spite of larger grain size obtained.
Laser activation method after ion implantation can lower the process temperature, and the TFT performance of laser activation is similar to that of conventional furnace activation. However, the leakage current for laser activation is higher than that for furnace activation, which is caused by grain modification near S/D side and will result in increased trap state density.
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