A Study on Novel Junctionless Poly-Si Thin Film Transistors by Monolayer Doping technology

• Main Authors: Huang, Ping-Cheng, 黃品烝
• Other Authors: Chao, Tien-Sheng
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/19099292253810304693

碩士 === 國立交通大學 === 電子物理系所 === 102 === Junctionless FETs are of great interest due to the elimination of ultra-shallow junction formation.Most importantly, Junctionless FETs has better suppression of short channel effect. However, there exists a big issue – prone to process variation on Junctionless FETs. Therefore, we proposed gradual channel doping junctionless field-effect transistor to suppress the variation and get the better electrical performance. In this study, we compared with three different kinds of devices- inversion mode FET, implant junctionlesss FET and SAM junctionless FET. In the simulation, we take device width 10nm and thickness 30nm as our base structure. We found that the gradual channel doping would close our device easier. In our experiment, We found that the novel SAM junctionless FETs show the most excellent electrical characteristics (e.g. low variation ,the well-situated Vth ,good S.S, and high on/off ratio ). The poly-Si SAM-junctionless with MWA annealing exhibit a very low threshold voltage (VTH ~-0.1V for p-type), steep with subthreshold swing (S.S. ~ 67 mV/dec) and high ION/IOFF ratio>107without hydrogen related plasma treatments. We scale the gate length down to 20nm. It still has good electrical performance.