A high-speed silicon-on-insulator (SOI) of a 1/8 frequency divider and
a 64-bit adder were realized using an optimized gate-overlapped LDD a
nd a self-aligned titanium silicide (TiSi2) source-drain structure. Th
e advantages of the delay time and power consumption were analyzed by
circuit simulation. The maximum operation frequency of the SOI divider
is 2.9 GHz at 3.3 V. The SOI divider operates about 1.6 times faster
than the bulk-Si divider. The power consumption of the SOI divider at
the maximum operating frequency is about 60% of that of the bulk divid
er. On the other hand, the speed of the SOI adder is 1.9 nsec at 3.3 V
. The SOI adder speed is about 1.3 times faster than the bulk adder. T
he power consumption of the SOI adder is about 80% of that of the bulk
divider. It was found that the high speed, low power features of the
SOI divider were due to the pass transistor which had low junction cap
acitance and little substrate bias effects, in addition to the low wir
ing capacitance and low fanout capacitance compared to the bulk adder.
As a result, it is suggested that SOI circuits using pass transistor
have a potential for GHz level systems and it is expected they will be
applied to handy communication systems and portable computers used in
the multimedia era.