hello all

    These days, I'm carrying through RIE etching of SiO2 thin film which is
about
500nm in thickness and deposited on Si wafer. My structure is 5um in linewidth,
and utilizes photoresist about 1.2um in thickness as mask. However, after RIE
was
finished, the linewidth was not actually 5um but with different width from 1um
to
4um, as shown in the picture. Before RIE etching, the whole wafer was put on a
hotplate 90s with temperature of 110 degrees in Celsiur scale. Can anybody
explain
how it happens and how I can solve this problem if I wanna get actually 5um
linewidth?

Best regards!