{HEAD ~ A regrowth} is performed on the exposed surfaces using an amphi conductivity impurity as {TAIL ~ a dopant}, such that a first portion having a first type conductivity is grown on the contact groove and a second portion having a second type conductivity is grown on the ridge 
{ HEAD ~ A regrowth } is performed on the exposed surfaces using an amphi conductivity impurity as { TAIL ~ a dopant } , such that a first portion having a first type conductivity is grown on the contact groove and a second portion having a second type conductivity is grown on the ridge
HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH