Abrupt pn junction diode formed using chemical vapor deposition processing

Abstract

A pn junction diode (250) having its metallurgical junction of the oppositely-doped regions (254, 256) coincident with the surface WS of an electrically-doped wafer W and a method of forming such a diode. The method includes preparing (202) the wafer surface prior to placing the wafer into a reaction chamber (14). The preparation of the wafer surface includes UV ozonation (102d) and hydrogen-termination (102e) 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 (252) 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 (204) 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 (257) is etched (206), the diode is passivated (208) and electrical contacts (258, 260) are formed (210) on the oppositely-doped regions of the pn junction.

Dependencies are inferred from the claim text.