{HEAD ~ An epitaxial layer} having {TAIL ~ an impurity concentration} different from that of the impurity layer is formed in the etched portion 
having
{ HEAD ~ An epitaxial layer } having { TAIL ~ an impurity concentration } different from that of the impurity layer is formed in the etched portion
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH