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