Patent ID: 7560325

Claim:
A method comprising: selectively etching a layer of regrowth mask material through one or more openings in a first mask to form a discrete raised region of semiconductor material having an upper surface and sidewalls, wherein the layer of regrowth mask material is on a first layer of semiconductor material which is on a second layer of semiconductor material which is on a third layer of semiconductor material which is on a substrate, wherein the second layer of semiconductor material is of a first conductivity type and wherein the first and third layers of semiconductor material are of a second conductivity type different than the first conductivity type, and wherein etching comprises etching through the layer of regrowth mask material and the first layer of semiconductor material to expose underlying second layer of semiconductor material in regions adjacent the first mask; removing the first mask such that the upper surface of the discrete raised region is covered by the regrowth mask material; epitaxially growing one or more layers of semiconductor material of the first conductivity type on sidewalls of the discrete raised region and on the second layer of semiconductor material adjacent the discrete raised region; and removing the regrowth mask material from the upper surface of the discrete raised region.