Dear colleagues: I am using EDP(ethylenediamine-pyrocathecol-water) to etch <100> silicon but the uniformity is not good and I don't know how to control the etch rate. Does any one like to tell me a typical composition for EDP, operating temperature and the relation between the etch rate and mol concentration of each reagent. By the way, any one has the experience of etching P++ silicon bridge out of the <100> N type silicon substrate using EDP? Thanks in advance for any help. -- Ma Bin 500, Yu Tian Road Shanghai Institute of Technical Physics The Chinese Academy of Sciences Shanghai 200083 P.R.C. Email: mabin@online.sh.cn Tel: 86-021-65420850-13323(13127)