Effect of p-Type Buried Layer Dose on Hot Carrier Degradation of $R_{{\mathrm{\scriptscriptstyle ON}}}$ in 700 V Triple RESURF nLDMOS

The degradation of ON-resistance (R
_ON
) caused by the hot-carrier injection in the 700 V triple reduce SURface field LDMOS is investigated in this letter. Experimental results show that the degradation of R
_ON
is reduced by increasing the dose of p-type buried layer (Pbury). The average R
_on
shift is only 3.7% after 168 h of aging tests with Pbury dose equal to 3.4 × 10
¹²
cm
^-2
. Both peak electric field and impact ionization rate near the bird's beak close to the source are decreased by increasing the dose of Pbury. Meanwhile, the peak electric field close to the drain is increased to avoid the drop in the breakdown voltage.