Patent ID: 9478646
Filing Date: 2016-10-25
CPC Classification: H01L

Claim Text:
1. A method for fabricating an anode-shorted field stop insulated gate bipolar transistor (IGBT), comprising: a) selectively forming first semiconductor regions of a first conductivity type within a top surface of a semiconductor substrate, wherein the first conductivity type is opposite a conductivity type of the substrate; b) growing a field stop layer of the first conductivity type onto the top surface of the substrate, wherein the field stop layer has a lower concentration of charge carriers than the first semiconductor regions; c) growing an epitaxial layer of the first conductivity type on top of the field stop layer, wherein the epitaxial layer has a lower concentration of charge carriers than the field stop layer; d) forming one or more insulated gate bipolar transistors (IGBT) component cells within the epitaxial layer; e) thinning a back surface of the substrate to a desired thickness and expose the first semiconductor regions; f) performing a blanket implant to form implant regions of a second conductivity type opposite that of the epitaxial layer and field stop layer within the back surface of the substrate, wherein is performed after the first semiconductor regions of a first conductivity type are formed on the top surface of the semiconductor substrate, wherein activation of the blanket implant is limited to minimal activation at less than 900° C.; and g) evaporating metal onto the back surface of the substrate.