Dry

If used in connection with plasma technology , this term refers to the dry execution of surface processes which otherwise require the use of wet chemicals (acids, alkaline or other solutions, solvents).

Accordingly, “dry asher”, “dry cleaner”, “dry etcher” and “dry oven” are terms describing the equipment for dry modification of materials via plasma technology.

Although dry chemical processes often work at much lower treatment speeds, especially etching rates, than wet chemical processes, they can be finely controlled so that adjustment options of the order of atomic layers are possible in some cases. 

The benefit of dry processes is that there is no need to store, handle and dispose of wet chemicals, which are without exception harmful to health and the environment, and that no chemicals need to be removed and no parts dried after treatment.

For more details see What is plasma