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.