Hi, Is there any simple way to check if holes are fully etched in DRIE process or not. I have one thin wafer 250 micron bonded with another wafer 450 micron. I am trying to achieve through holes in first Si wafer(min hole dia is 30 microns), but my lab does not have any instrument to check if holes are fully etched or not. I have to stop DRIE process, then have to remove wafer and then again have to bond wafers to check the etched holes thickness. (whole process 2-3) I will thankful to any one who can let me know any method to check it. -- Thanks, Pradeep Dixit Research Student, Micromachine Center, NTU Singapore - 639669