The chemical stability of polycrystalline diamond subjected to common silicon device integrated circuit process steps has been investigated using Raman spectroscopy, scanning electron microscopy, I-V, and capacitance-voltage. Wet chemical process steps such as RCA cleaning, KOH etching, and aluminum etching were performed without significant degradation of the diamond. No contamination, as judged from electrical data, of reference metal oxide semiconductor capacitors from the diamond was seen during furnace treatments. Diamond was found to withstand annealing at 950 degrees C without electrical degradation. Patterning of diamond was demonstrated and utilized in manufacturing of test structures. Methods have been found to protect the diamond at temperatures up to 1100 degrees C during thermal oxidation of adjacent silicon. Capping layers consisting of silicon nitride, silicon nitride on top of chemically vapor deposited oxide and polysilicon were found to protect diamond during thermal oxidation. A silicon-on-diamond wafer process based on process steps investigated in this paper is proposed.