Ballistic models of diamond growth in two dimensional space are studied in detail. A new probabilistic model is introduced to simplify and reduce computation, and successfully compared with the etchant model which was proposed recently by Capraro and Bar-Yam. The growth process is shown to be divided into three distinct stages, and the limit of the expected thickness of the diamond film is indicated. The relation between the incident angle and growth direction is discussed. Analytic equations for the density of the resulting pattern are given and a scaling analysis is performed
