Characterization of ohmic and Schottky contacts on SiC

Electrodeposition of Ni/SiC contacts

“…Barrier heights reported for 4H-SiC/Ni junctions prepared by physical deposition methods are in the range between 1.2 and 1.7 eV, depending on the measurement technique and surface preparation. 6,14,18 The large difference between the values for the barrier height from the two methods and the high ideality factor obtained here suggests the presence of interface states or an inhomogeneous Schottky barrier. 9,34,35 Figure 9 also shows the current-potential curve for a 4H-SiC/Ni junction after annealing at 950°C in a reducing atmosphere, illustrating that the junction becomes Ohmic.…”

“…6,9,10 For n-type SiC, Ohmic contacts have been prepared by evaporation or sputter deposition of nickel or nickel-based films followed by subsequent annealing. [11][12][13][14][15][16][17][18] In this article, we report on the fabrication and characterization of n-type 4H-SiC/Ni contacts by electrodeposition.…”

Effects of annealing temperature on the structure and electrical properties of tungsten contacts to n-type silicon carbide

“…Although at present Ni/SiC ohmic contacts of satisfactorily low resistivity in the range 10 −6 -10 −7 cm 2 [8] can be obtained, they are prone to degradation during prolonged work at an elevated temperature. It was suggested that graphite phases, which are formed as a result of a thermally induced reaction between Ni and SiC during the annealing of the Ni/SiC structure, can be responsible for their thermal instability [9,10]. Moreover, carbon layer deposition on the surface of Ni/SiC after annealing can pose a problem with the mounting of the wire [11].…”

Radiation effects on ohmic and Schottky contacts based on 4H and 6H-SiC

“…So far, many different metals have been used as both ohmic and SC material such as Ni, Al, Co, Ti, Au and W. In addition, because of its superior advantages such as refractory nature, producing low ohmic contact resistivity [3][4][5][6][7][8][9][10][11] and high SBH [12][13][14][15], Ni has been generally chosen as the contact material both for ohmic and SCs in SiC [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. The effects of high-energy proton irradiation and highdose gamma ray irradiation on 4H-SiC Schottky rectifiers have been investigated by Nigam et al and Kim et al respectively, [17,18].…”