Patent ID: 7745882
Filing Date: 2010-06-29
Classification: H01L

Abstract:
1. A bipolar junction transistor, comprising: a collector region of a second conductive type formed in a substrate of a first conductive type and isolated by a device isolation layer; a buffer region of the second conductive type formed within the collector region and being deeper than the device isolation layer; a base region of the first conductive type formed within the collector region, isolated from the buffer region by the device isolation layer and being shallower than the device isolation layer; an emitter region of the second conductive type formed within the base region of the first conductive type; and a collector contact of the second conductive type formed in the buffer region of the second conductive type, wherein the emitter region in the base region and the collector contact in the buffer region are formed with substantially the same vertical thickness from a top surface of the substrate.