Abrupt pn junction diode formed using chemical vapor deposition processing

The invention relates to forming a pn junction in a semiconductor structure and, in particular, to forming a hyper-abrupt pn junction by low-temperature growth of a doped film on a surface of an oppositely doped substrate wherein the metallurgical junction of the pn junction could coincide with the surface of the substrate. A pn junction diode () having its metallurgical junction of the oppositely-doped regions () coincident with the surface WS of an electrically-doped wafer W and a method of forming such a diode. The method includes preparing () the wafer surface prior to placing the wafer into a reaction chamber (). The preparation of the wafer surface includes UV ozonation () and hydrogen-termination () in a hydrofluoric acid solution. After the wafer surface is prepared, the wafer is inserted into the reaction chamber and heated to a temperature of less than 650° C. Without delay, a pn junction () is formed by growing on the wafer surface an epitaxial film layer having a doping opposite the doping of the wafer. The doped film layer is grown () by plasma-enhanced chemical vapor deposition while simultaneously introducing dopant atoms into the reaction chamber. After the film layer has been grown, a mesa structure () is etched (), the diode is passivated () and electrical contacts () are formed () on the oppositely-doped regions of the pn junction.