One or more embodiments relate to a power transistor including a support layer formed of a first material and an active region formed of a second material.
Power MOSFETs have a maximum specified drain to source voltage, beyond which breakdown may occur. Exceeding the breakdown voltage causes the device to turn on, potentially damaging it and other circuit elements due to excessive power dissipation. The drain current should stay below a certain specified value which is limited by heating due to resistive losses in internal components such as bond wires or metal layers. The junction temperature of the MOSFET should stay under a specified maximum value for the device to function reliably. The maximum value is given by the power dissipation times the junction-to-case thermal resistance, which is intrinsic to the device and depends on the material of the device. As conventional power transistors are formed of silicon the material characteristics of silicon are effecting limits of operation for these power transistors.
For these and other reasons, there is a need for the present invention.