Patent ID: 7635599
Filing Date: 2009-12-22
Classification: B82Y,G01R,G11B,H01L

Abstract:
1. A method of making a three terminal magnetic sensing device comprising the steps of: providing a collector substrate having an elevated central region and a recessed side regions adjacent the elevated central region, the elevated central region comprising a top surface surrounded by angled sidewalls; forming a first insulator layer over the recessed side regions and the angled sidewalls of the elevated central region; forming a base lead layer over the first insulator layer in the recessed side regions and the angled sidewalls of the elevated central region, the base lead layer being formed in-plane with the elevated central region; forming, over the elevated central region, a sensor stack structure having an emitter and a base, the base being absent from the recessed side regions, the base having an end which is formed on top of and in contact with an end of the base lead layer in the elevated central region over one of the angled sidewalls; forming, in one of the recessed side regions, a second insulator layer over the base lead layer and adjacent the sensor stack structure; and forming, in the one recessed side region, a conductive base lead in a via hole through the second insulator layer down to the base lead layer.