Ohmic contacts to InP-based materials induced by means of rapid thermal low pressure (metallorganic) chemical vapor deposition technique

A rapid-thermal-low-pressure-metallorganic-chemical-vapor-deposition (RT-LPMOCVD) technique was executed in order to deposit non-semiconductor thin layer materials, necessary for producing metal contact to InP-based microelectronic devices. Silicon dioxide (SiO) films were deposited onto InP substrates in rapid thermal cycles, using O and 2% diluted SiH in Ar, with very fast growth kinetics and low activation energy. The SiO film exhibited excellent properties, such as refractivity index, density, internal stress, and wet p-etch rates. The SiO films were dry etched in a given pattern to allow for the formation of a small metal contact to the InP-based material, onto which the SiO layer was deposited. Subsequently, titanium-nitride (TiN) thin films were deposited onto the InP substrate through rapid thermal deposition cycles, using a tetrakis (dimethylamido) titanium (DMATi) metallorganic liquid source as the precursor for the process, with fast kinetics. The deposited TiN films had a stoichiometric structure and contained nitrogen and titanium in a ratio close to unity, but incorporated a large amount of carbon and oxygen. The film properties, such as resistivity (40-80 μΩ·mm) and stress (compressive; -0.5 to -2.0×10 dyne·cm), were studied in addition to an intensive investigation of its microstructure and morphology, and their performance as an ohmic contacts while deposited onto p-InGaAs material (Zn doped 1.2×10 cm). © 1991 The Minerals, Metals & Materials Society.