Patent ID: 6077752
Filing Date: 2000-06-20
Classification: H01L

Abstract:
A method of manufacturing a bipolar transistor having a self-registered base-emitter structure, comprising the steps of:depositing a layer of amorphous silicon on a substrate of crystalline silicon having an upper region of a first conductor type;doping the amorphous silicon layer with a dopant to form a second conductor type;depositing at least one dielectric layer on the amorphous silicon layer in a manner such as to prevent crystallization of the amorphous silicon layer;patterning the resultant structure and thereafter etching away the dielectric layer and the amorphous silicon layer within a predetermined region such as to define an emitter opening;growing a thermal oxide on the resultant structure, wherein the amorphous silicon layer is converted to a polycrystalline silicon layer;forming an intrinsic base of the same conductor type as said polycrystalline layer by doping through the thermal oxide;depositing a layer of electrically insulating material on the resultant structure and thereafter etching the structure anisotropically until a thin oxide layer remains on the substrate in the emitter opening and in such a manner that a spacer of said electrically insulating material remains along the side walls of the emitter opening;removing said thin oxide layer;forming an emitter contact in the emitter opening and doping said emitter contact to said first conductor type; andheat-treating the structure to form an emitter-base junction in the substrate by out diffusion of the dopants from the emitter contact.