Patent ID: 8759188
Filing Date: 2014-06-24
Classification: H01L

Abstract:
1. A method for integrating a bipolar transistor in a semiconductor chip having a main surface covered by a sacrificial insulating layer, the chip including a collector region of a first type of conductivity extending from a main surface of the chip, the method comprising steps of: forming an intrinsic base region of a second type of conductivity, the intrinsic base region extending in the collector region from the main surface under an intrinsic base window of the sacrificial insulating layer, forming an emitter region of the first type of conductivity, the emitter region extending in the intrinsic base region from the main surface under an emitter window of the sacrificial insulating layer, removing the sacrificial insulating layer, forming an intermediate insulating layer on the main surface, the intermediate insulating layer having a thickness lower than a thickness of the sacrificial layer, and forming an extrinsic base region of the second type of conductivity, the extrinsic base region extending in the intrinsic base region from the main surface under an extrinsic base window of the intermediate insulating layer, the extrinsic base region having a concentration of impurities higher than a concentration of impurities of the intrinsic base region and being separated from the emitter region by a portion of the intrinsic base region.