Source/Drain Doping Modulation and Current-Voltage Character- isitcs of Deep Sub-micron SOI MOSFET's by Computer Simulation

• Main Authors: Lin ,Hwang-Chi, 林煌琦
• Other Authors: Liao,Sen-Mao
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/32230501715838263571

碩士 === 中原大學 === 電子工程學系 === 84 === Deep sub-micron SOI(Silicon-on-Insulator)MOSFET's is one of the researched-actively devices at present. In this paper, we will discuss the related current-voltage characteristics of SOI MOSFET's devices of different source/drain modulation. We employ the TMA's simulation programs-TSUPREM-4 and MEDICI on simulating the processes and characteristics of SOI devices respectively. By adjusting the ion implantation does ,we can get the different doping profiles and concentration. From these variant doping conditions ,the different I-V curves will show, and we can find that the threshold voltage ,Vth, rolling off with the increase in implantation dose. It shows the short- channel-effect becomes dominant.Besides, the increase in implanted dose always accompanies the shrinking of effective channel length, this phenomenon turns the short-channel-effect more obvious. In order to improve these negative phenomenons, we propose three methods : (1)Drain/source ion-implanted after increasing the width of gate spacer. By this way, the shrinking of effective channel length caused by thermal intrinsic diffusion can be alleviated.(2)Adopting the LDD(Lightly Doped Drain)structure restrain the influence of hot-electron- effect.(3)By adjusting the right channel doping concentration, I can reduce the threshold voltage sensitivity and rolling-off. These three methods mentioned above all can solve the short- channel-effect problems in deep sub-micron SOI devices effectively. The mathematical medels of other papers are used to verify the results of computer simulations. The technologies of deep sub-micron SOI MOSFET's keep improving at any aspects continuously. For the vision of future, the inherent advantage of very small parasitical capacitance, the higher cut off frequency, and the low power dissipation , those make DOI MESFET's have the huge potential to be an attractive devices, besides, the higher density of packaging, make it can be produced with 3-D devices technology. Since the