Hello! Everybody I am observing ditches at the periphery of diaphragm etched in silicon with KOH etching. These ditches are at the intersection of etch front i.e. 100 plane and sloped wall i.e. 111 plane and are 2-3 micron deep. I am using 40% HOH at 80 deg. C. We also observed same problem with Isopropyl alcohol (IPA) addition. Can anybody suggest the cause and solution of this problem. RAJKUMAR SCL, India