This chapter deals with the physical and chemical processes which take place in fluorocarbon plasmas. Emphasis is given to plasma diagnostic techniques which are well suited to investigate the neutral and ionized gas phase species as well as plasma-surface interactions. Special attention is given to a description of mechanisms which control plasma etching and plasma polymerization. Structural characterization techniques which work well with a variety of fluorocarbon thin films prepared in a plasma are given and key physical properties of such films are reviewed.