The deposition of diamond by different techniques on Si wafers of up to 8 in diameter has been reported by various groups. The uniformity of these blanket coatings is indicated to be of the order of +/- 10%. The commonly-used method of enhancing nucleation by scratching is not recommended for Si wafers, especially for selective-area diamond deposition. The selective area deposition of diamond on 4 in Si wafers has become possible by use of the standard lift-off technique as practised in ordinary microelectronic processing. The pretreatment is applied after masking on the free Si-substrate surface. A photoresist film is deposited either on Si wafers or on Si3N4 and/or SiO2 precoated (>1000 Angstrom) Si wafers by spin-coating, using a mask to obtain the desired pattern. Following a special pretreatment step of the selectively masked wafer surface, the photoresist is dissolved in acetone, then diamond is deposited. The diamond coating can be formed with or without boron doping. By this technique, thermistors and other sensor devices have been developed.