Referring to FIG 2D, {HEAD ~ interlayer dielectric layer} 12 is etched using {TAIL ~ second photosensitive layer pattern PR2} and the reaction by product spacers R as etching masks to form a trench 
is etched using
Referring to FIG 2D , { HEAD ~ interlayer dielectric layer } 12 is etched using { TAIL ~ second photosensitive layer pattern PR2 } and the reaction by product spacers R as etching masks to form a trench
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH