A buried layer with doping of a second conductivity type is formed in a first region of {HEAD ~ the semiconductor layer}, wherein the buried layer is produced at the junction between {TAIL ~ the semiconductor layer} and semiconductor substrate 
A buried layer with doping of a second conductivity type is formed in a first region of { HEAD ~ the semiconductor layer } , wherein the buried layer is produced at the junction between { TAIL ~ the semiconductor layer } and semiconductor substrate
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 OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH