Patent ID: 7556994

Claim:
A method comprising: positioning a first mask on a layer of n-type semiconductor material, wherein the layer of n-type semiconductor material is on a first layer of p-type semiconductor material and the first layer of p-type semiconductor material is on a substrate; selectively etching the layer of n-type semiconductor material through openings in the first mask to form an etched region and a raised region having a sidewall adjacent the etched region; removing the first mask; positioning a second mask on the layer of n-type semiconductor material which masks a portion of the etched region and a portion of the raised region; implanting n-type dopants in the layer of n-type semiconductor material through openings in the mask to form a first non-implanted region over the etched region, a second non-implanted region over the raised region and n-type implanted regions in the layer of n-type semiconductor material; removing the second mask; epitaxially growing a second layer of p-type semiconductor material on the etched and implanted layer of n-type semiconductor material; positioning a third mask on the second layer of p-type semiconductor material which masks a portion of the second layer of p-type semiconductor material over the first non-implanted region and a portion of the second layer of p-type semiconductor material over the second non-implanted region; using the third mask, selectively etching through the second layer of p-type semiconductor material to expose implanted regions in the underlying layer of n-type semiconductor material thereby forming raised features of p-type semiconductor material; removing the third mask; and forming ohmic contacts on the raised features and on the implanted regions in the layer of n-type semiconductor material.