Active solid-state devices (e.g. – transistors – solid-state diode – Field effect device – Having insulated electrode
Reexamination Certificate
2001-07-17
2002-08-20
Wojciechowicz, Edward (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Field effect device
Having insulated electrode
C257S329000, C257S330000, C257S336000
Reexamination Certificate
active
06437390
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to MOSgated devices and more specifically relates to a novel structure for a MOSgated device with a reduced gate-to-drain capacitance.
The periodic charging/discharging of the parasitic gate-drain (Miller) capacitance of a MOSFET during each switching cycle is known to increase the power dissipated within the conventional trench-gate MOSFET structures. This decreases the efficiency of the power system and limits the operating frequency of the MOSFETs. Furthermore, the gate-drain capacitance makes the MOSFET susceptible to spurious turn-on, induced by a rapidly changing drain voltage (dv/dt induced turn-on). Sometimes, this leads to the destructive failure of the MOSFET. The novel reverse source-drain FET structures of this invention significantly reduces the gate-drain capacitance and susceptibility to spurious turn-on.
BRIEF SUMMARY OF THE INVENTION
A significant portion of the gate-drain capacitance (Cgd) of a conventional MOSFET is the oxide capacitance (Cox) in the gate-drain overlap area. The oxide capacitance (Cox) is inversely proportional to the oxide thickness (tox) in the gate-drain overlap region and directly proportional to the gate-drain overlap area. In accordance with the invention, the arrangement of the source and drain electrodes (with respect to the gate electrode) is reversed. The reversed source-drain FET structure significantly lowers the gate-drain capacitance by reducing the overlap area of gate and drain and by increasing the oxide thickness between the gate and the drain electrodes.
REFERENCES:
patent: 6124611 (2000-09-01), Mori
International Rectifier Corporation
Ostrolenk Faber Gerb & Soffen, LLP
Wojciechowicz Edward
LandOfFree
Reversed source-drain mosgated device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reversed source-drain mosgated device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reversed source-drain mosgated device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2944484