Patent ID: 7573080

Claim:
A transient suppression semiconductor device, comprising a collector layer made of a first semiconductor material of a first conduction type, a base layer made of a second semiconductor material of a second conduction type opposite to said first conduction type, an emitter layer made of a third semiconductor material of said first conduction type, stacked in this order sequentially on a top side of a substrate; wherein an emitter-base depletion region expands across said emitter and base layers; a base-collector depletion region expands across said base and collector layers; said third semiconductor material is different from said second semiconductor material; said third semiconductor material has a bandgap larger than that of said second semiconductor material; said base layer has a doping concentration higher than that of said emitter and collector layers; said collector layer has a thickness less than 300 nm; and said base layer has a thickness larger than the sum of the thickness of a section of said emitter-base depletion region that extends into said base layer and the thickness of a section of said base-collector depletion region that extends into said base layer.