Comparison of Short-Circuit Safe Operating Areas Between the Conventional Field-Stop IGBT and the Superjunction Field-Stop IGBT

This paper studies the short-circuit safe operating area (SCSOA) of the conventional field-stop (FS) IGBT and the superjunction (SJ) FS IGBT, based on 1200 V-rated samples, with the help of numerical electrothermal simulations. The results show that the peak electric field influences the distribution of the temperature inside devices and plays a crucial role in determining their SCSOAs. When the doping concentration of the collector,
$\text{N}_{\mathrm{ C}}$
, is low, the peak electric field exits near the collector. Both types of IGBTs have a long short-circuit time,
$\text{T}_{\mathrm{ SC}}$
, which can exceed
$15~{\mathrm {\mu }}\text{s}$
.
$\text{T}_{\mathrm{ SC}}$
decreases with the increase of
$\text{N}_{\mathrm{ C}}$
because the peak electric field transfers to near the channel. The introduction of the SJ structure weakens the peak electric field and increases
$\text{T}_{\mathrm{ SC}}$
. The difference is at least 4
$\mu \text{s}$
and up to 6.87
$\mu \text{s}$
, when
$\text{N}_{\mathrm{ C}}$
ranges from 2.0
$\times \,\,10^{17}$
cm
$^{-3}$
to 1.1
$\times \,\,10^{18}$
cm
$^{-3}$
. Besides,
$\text{T}_{\mathrm{ SC}}$
of the SJ IGBT can be increased by using highly-doped pillars.