Method for manufacturing a semiconductor device and suppressing the generation of bulk microdefects near the substrate surface layer

Claim 1

A method for manufacturing a semiconductor device having in a semiconductor substrate of one conductivity type a deep island-like diffusion layer of the opposite conductivity type, said method suppressing the generation of bulk microdefects near the substrate surface layer and comprising the steps of: selectively forming in the semiconductor substrate of one conductivity type a deep island-like impurity diffusion layer of the opposite conductivity type, including the substeps of, forming an oxide film on the semiconductor substrate; forming a resist pattern on the oxide film; implanting an impurity ion into the substrate at a predetermined location; forming a well by heating the substrate at a temperature greater than 1100° C. in a gas comprising H 2 and one of N 2 , Ar, Ne, He or a mixture thereof; and removing the oxide film; forming a field oxide film, serving as an element isolation layer, next to the impurity diffusion layer; forming a first gate, serving as a capacitor, on the semiconductor substrate; forming a second gate, serving as a switching transistor, on the semiconductor substrate and connected in parallel with the first gate; forming an insulation layer for insulating the first gate from the second gate; and forming a passivation film for protecting an element uppermost on the insulation layer.

Claim 2

A method for manufacturing a semiconductor device having in a semiconductor substrate of one conductivity type a deep island-like diffusion layer of the opposite conductivity type, said method suppressing the generation of bulk microdefects near the substrate surface layer and comprising the steps of: selectively forming in the semiconductor substrate of one conductivity type a deep island-like impurity diffusion layer of the opposite conductivity type, including the substeps of, forming an oxide film on the semiconductor substrate; forming a resist pattern on the oxide film; implanting an impurity ion into the substrate at a predetermined location; forming a well by heating the substrate at a temperature greater than 1100° C. in a gas comprising H 2 and one of N 2 , Ar, Ne, He or a mixture thereof; and removing the oxide film; forming a field oxide film, serving as an element isolation layer, next to the impurity diffusion layer; forming a first gate, serving as a capacitor, on the semiconductor substrate; forming a second gate, serving as a switching transistor, on the semiconductor substrate and connected in parallel with the first gate; forming an insulation layer for insulating the first gate from the second gate; and forming a passivation film for protecting an element uppermost on the insulation layer.