| Summary: | 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
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