Cascade-Connected Low-Voltage MOSFETs Operating as One High-Voltage MOSFET\

Power integrated circuits require integrating devices with multiple rated voltages, but integration of high-voltage devices poses challenges such as the need for special wafer specifications and an increase in process steps. We propose a monolithically integrated cascade-connected low-voltage metal-oxide-semiconductor field-effect transistors (MOSFETs) operating as one high-voltage MOSFET, consisting only of low-voltage enhancement MOSFETs. In cascade-connected
$n$
-MOSFETs, two enhancement
$p$
-MOSFETs with gates and drains connected to each other are connected between the gates of the enhancement
$n$
-MOSFETs in series. The cascade-connected
$p$
-MOSFETs have a structure in which
$p$
-MOSFETs in the cascade-connected
$n$
-MOSFETs are replaced with
$n$
-MOSFETs, and
$n$
-MOSFETs are replaced with
$p$
-MOSFETs, and the connection relationships between the gate, drain, and source are the same. We confirmed our cascade-connected MOSFETs' static characteristics and switching operation as a high-voltage MOSFET. The breakdown voltage of the cascade-connected MOSFETs increased in proportion to the number of series connections, reaching over 800 V for 29 series. From the above results, cascade-connected MOSFETs are promising for integrating devices with various rated voltages.