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