Experiments of Sub-Micron Superjunction Devices With Ultra-Low Specific On-Resistance

A sub-micron superjunction (SM SJ) device with ultra-low specific on-resistance
${R}_{\text {on},{sp}}$
is proposed and experimentally realized in this letter. The new device features a surface SM SJ with a mean ion implantation depth of 190 nm and a bulk curvature effect suppressing layer (CSL) with a junction depth of
$3.7~\mu \text{m}$
. The highly doped SM SJ acts as a ultra-low resistance current path to reduce the specific on-resistance
${R}_{\text {on},{sp}}$
meanwhile the CSL shields the possible curvature effect for high breakdown voltage
${V}_{\text {B}}$
. Experiments of the SM SJ device demonstrated a significantly increased total N-type doping dose up to
$9.7\times 10^{{12}}$
cm
$^{-{2}}$
that is almost 10 times of the conventional RESURF dose. A measured low
${R}_{\text {on},{sp}}$
of 27.8
$\text{m}\Omega \cdot $
cm
²
was observed under a
${V}_{\text {B}}$
of 622.6 V, realizing a high figure of merit
FOM
=
${V}_{{\text {B}}^{{2}}} / {R}_{\text {on},{sp}}$
of 13.94 MW/cm
²
and a reduction of 62.2% when compared with the theoretical limit of the triple RESURF technology under the same
${V}_{\text {B}}$
.