STUDY THE EFFECT OF GATE OXIDE THICKNESS AND LDD DOPING PROFILE ON THE PERFORMANCE OF LDMOS BY USING SIMULATOR

LDMOS is a silicon deviceand has been provento be a populardevice in high power
RF application. It has excellent efficiency, linearity and peak power capability. The
LDMOS roadmap is always to improve intrinsic die performance in key areas such
as efficiency, gain and continuing focus on cost - effective device packaging. The
objective ofthis work is to study the effect of gate oxide thickness and LDD doping
profile on performance ofLDMOS for high power RF applications by using Silvaco
TCAD simulator as a part of work to improve its performance. The work is done by
varying the gate oxide thickness, Tox from 200 Aup to 700 Aand varying LDD
doping profile, ND from 2xl010cm"3 to 2xl013cm"3. The performance ofLDMOS is
analyzed by investigating the effect on the following parameters: VT> gm,fu Ciss, BV.
Theresults obtained shows that as gate oxide thickness, Tox is increased; VT and/, are
increased while magnitude of gm, Ciss and BV are reduced. Besides, as LDD
concentration, ND is increased, VT, magnitude of gm, and / are increased while
magnitude of C^, and BFare reduced. The fundamental of semiconductor device
fabrication is studiedand understood while the knowledge of using both process and
device simulator (Athena & Atlas) has been acquired.