Analyses and Experiments of Ultralow Specific On-Resistance LDMOS With Integrated Diodes

An ultralow specific on-resistance (
${R} _{\mathrm{ on,sp}}$
) accumulation-mode LDMOS (ALDMOS) is proposed and investigated by simulations and experiments. The proposed ALDMOS features two separated integrated diodes (SID) above the N-drift surface, which forms high density electron accumulation layer in the on-state. Meanwhile, the SID not only assists depleting the N-drift to increase the N-drift doping centration (
${N} _{\mathrm{ d}}$
) in the off-state, but also modulates the lateral electric field to improve the breakdown voltage (
BV
). Thus, the proposed SID ALDMOS could achieve ultralow
${R} _{\mathrm{ on,sp}}$
and maintain high
BV
simultaneously. The layout and key fabrication processes of the SID ALDMOS are demonstrated. The measured results show that the SID ALDMOS realizes a
BV
of 483V and
${R} _{\mathrm{ on,sp}}$
of 29.3m
$\boldsymbol{\Omega } $
.cm
²
, with a high FOM value of 7.96MW/cm
²
. Its
${R} _{\mathrm{ on,sp}}$
is decreased by 33.7% compared with triple RESURF LDMOS at the same
BV
.