Many of you may be annoyed by my question. I'm sorry in advance. I've just finished my M.S. in Materials Science & Engineering, and have gotten an offer as a Semiconductor Process Engineer. The specialty is lithography and wet chemistry - including wet etching. As an MSE student I learned to be horrified with Hydrofluoric Acid. I'm not a fan of other strong acids, but HF terrifies me. I imagine that I might be mixing acids, and some HF gets on my skin, or I breath it in. Or I might be dipping a wafer in an HF bath and splash some on me. I know, there are safety procedures - splash goggles, protective clothing, respirator, etc. But I always make room for the one time I have an oversight, or when the gloves have a small cut, or the respirator isn't working right. I'll be honest - I don't know very well how the etching is done, mostly because I've never seen it done. I don't know if specialized machines handle the acid for you, so that you're not directly exposed to it. Am I worrying unnecessarily? How hazardous is etching engineering? Can some of you tell me how the whole process works - do you mix the acids manually, and dip the wafer manually during the R & D efforts? Or do machines handle the acid part for you? One day I'll look at comments like this and, just like you, probably be very annoyed. But, as a pure newbie, I would love some kind answers. Thanks!