A high power switch includes diode and BJT structures interdigitated in a drift
layer and separated by insulated trench gates; electrodes contacting the diode
and BJT structures provide anode and cathode connections. Shallow N+ regions extend
below and around the corners of the oxide side-walls and bottoms of respective
gates. A voltage applied across the anode and cathode sufficient to forward bias
the diode's p-n junction causes electrons to be injected which provide a base drive
current to the BJT sufficient to turn it on and enable current to flow from anode
to cathode via the diode and BJT structures. A gate voltage sufficient to reverse
bias the junction between the shallow N+ regions and the drift layer forms a potential
barrier which blocks current flow through the diode and BJT structures and eliminates
the base drive current such that the BJT and said switch are turned off.
