Carbide contacts on homoepitaxial diamond films

Deep Level Spectroscopy in Homoepitaxial Diamond Films Studied from Current Transients in Schottky Junctions

“…The typical doping concentrations of the samples studied here are between 5 Â 10 16 and 2 Â 10 17 B/cm 3 . Metallic contacts are made with several techniques, depending on the following purpose: a Mo 2 C forming procedure is used for ohmic contacts while either aluminium or erbium carbide is deposited or formed to achieve Schottky contacts [5]. In the latter case, rectification ratios of three orders of magnitude can be obtained up to 500 C while the maximum temperature of operation for our Al diodes is practically limited to 250 C because the chemical stability of the contact is no more ensured at higher temperatures.…”

Ohmic contacts study of P+N diodes on (111) and (100) diamond

“…The fabrication process starts with the definition of the n-region by using ICP-RIE dry etching with Ar/O2 and CF4/O2 optimized plasma steps [5], using an Al metallic mask in order to reach the p + underlayer. The Ti(50nm) / Pt(50nm) / Au(500nm) stack for the n and p-type ohmic contacts is then deposited with a single lift-off step [6]. To do that we have developed a specific lithography process available for very small samples such as diamond substrates.…”

Potential barrier heights at metal on oxygen-terminated diamond interfaces

“…These are mainly good adhesion, thermal and chemical stability at elevated temperatures, compatible with the superior possibilities of diamond, and potential barriers ensuring both low electrical losses under forward voltage and minimal reverse currents even at high temperatures. Several attempts have been proposed, relying either on materials which react with the bare surface of diamond to form carbides, like silicon [3] or refractory metals and compounds [4][5][6], even hetero-epitaxially grown on diamond [7], or metals on either the oxygenated or hydrogenated surface of diamond [8][9][10][11][12]. On bare diamond surfaces, potential barriers close to 2 V, stable at temperatures higher than 500℃ have been obtained but reverse current densities and ideality factors were much greater than expected from the thermionic mechanism alone at least at room and moderate temperatures, and some of these contacts were ohmic.…”