The polysilicon layer 32 is made of {TAIL ~ polysilicon} doped with {HEAD ~ impurity ions}, for example 
The polysilicon layer 32 is made of { TAIL ~ polysilicon } doped with { HEAD ~ impurity ions } , for example
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH