1063-7397/03/3202- $25.00 © 2003 MAIK “Nauka /Interperiodica”
Russian Microelectronics, Vol. 32, No. 2, 2003, pp. 75–78. Translated from Mikroelektronika, Vol. 32, No. 2, 2003, pp. 97–101.
Original Russian Text Copyright © 2003 by Korolev, Tikhonov.
Smart power switches provide a link between digital
control logic and a power load and perform power con-
trol, sensing/protection, and interfacing . In such
switches, power metal–oxide–semiconductor (MOS)
ﬁeld-effect transistors (MOSFETs) are mostly imple-
mented by vertical double-diffused MOS technology,
since this approach offers the maximum operating cur-
rents and breakdown voltages. However, the substrate
serves as the drain in this type of MOSFET and there-
fore is unsuitable for protection and control circuits.
By contrast, the planar design makes it possible to
produce both power transistors  and support circuits
by uniﬁed, complementary MOS (CMOS) technology.
Previous research [3–9] along this line has yielded a
planar power MOSFET for smart power CMOS
In this study, we designed, fabricated, and tested a
planar MOSFET with an octagonal gate region, as
shown in Fig. 1. Since an octagonal drain is a better
approximation of a circle than a tetragonal one, the
former conﬁguration has reduced electric ﬁelds at the
corners and hence makes for a higher breakdown volt-
age. With an octagonal gate, the area of an individual
MOSFET is 20% less than that of a tetragonal-gate
MOSFET (previous version), owing to a smaller source
Planar Power MOSFETs for Smart Power CMOS Switches
M. A. Korolev* and R. D. Tikhonov**
* Moscow Institute of Electronic Engineering (Technical University), Tsentral’nyi pr. 5, Moscow, 124498 Russia
** Technological Centre, Moscow Institute of Electronic Engineering (Technical University),
Tsentral’nyi pr. 5, Moscow, 124498 Russia
Received March 5, 2002
—Planar power MOSFETs with an octagonal gate are designed, fabricated, and tested. The implanta-
tion dose of the pinch-resistor region is optimized for off-state breakdown voltage times on-state resistance by
Octagonal-gate power MOSFET.
MICRO- AND NANODEVICES