An advanced p-channel LDMOS FET with HTRB tolerability of high-voltage pulse transmitter ICs for ultrasound applications

Novel +/-100-V p-channel LDMOS FET technology were developed for a pulse transmitter IC for an ultrasound application. With a design of steep-profile in drift region for a higher RESURF effect, area efficiency of the output performance can be improved by 20 % of R
_{on, sp}
. By an optimization of gate poly-Si structure for reducing electric field and higher tolerability against electron trapping in LOCOS, stable performance against high-temperature reverse bias (HTRB) can be obtained. BV
_off
/R
_{on, sp}
of 260 V/3079 ohm·mm
²
of p-channel LDMOS and well matched I
_D
-V
_DS
curve traces between n-channel and p-channel LDMOS FETs enabled the suitable bipolar pulse mirror symmetry with less than -40 dBc of second harmonic distortion in the IC with long-term stability.