A technique that produces submicron size features by machining GaAs wafers in air was studied. An apparatus was built which uses a sharp diamond tip to mechanically scribe patterns into the substrate. The debris produced from surface machining was removed by using a CO2 "snow jet" sprayer, thus eliminating the use of hazardous liquid chemicals for cleaning. By changing the force between the diamond tip and sample surface, different depths.of cuts were produced. This allowed the production of three dimensional patterns on the wafer in one step. With this instrument, write speeds of up to 25 mu m/s on 30 mu m x 30 mu m area patterns with a lateral resolution of 100 nm were demonstrated. In a different set of experiments, x-ray diffraction, spectroscopic ellipsometry, and cross sectional transmission electron microscopy analysis identified that subsurface damage created during the diamond turning process was removed at normal molecular beam epitaxial growth temperatures. Atomic force microscope analysis showed that the surface patterns were still present after annealing.