Design And Research Of Mo-C/4H-SiC Schottky Diode

Silicon carbide(SiC),as a third-generation semiconductor material,has become a hot topic for recent research due to its excellent characteristics.When researching silicon carbide devices,it can be found that the contact quality of metal and semiconductor will directly affect the electrical characteristics of silicon carbide devices,thereby affecting the application of the devices.How to prepare good Schottky contacts is the core issue of metal semiconductor contacts.In recent years,some studies have shown that the interface of Mo/4H-SiC Schottky contact exhibits serious barrier inhomogeneity.This is because metallic molybdenum will undergo a solid-phase reaction with the semiconductor interface,resulting in uneven SiC interface.Therefore,we believe that excessive reaction between the metal and SiC interface should be avoided as much as possible to form a uniform Schottky contact interface.In this paper,a new structure of silicon carbide diodes using Mo-C alloy as Schottky contact metal is proposed,and the effect of annealing temperature on the electrical characteristics of the manufactured devices is studied.Some important electrical parameters of Schottky can be obtained through current-voltage(I-V)and capacitance-voltage(C-V)tests at room temperature.Observe the uniformity characteristics of Schottky barrier through current-voltage-temperature(I-V-T)measurement.And through studying the field plate structure with different dielectrics.In addition,material characterization and analysis were performed by transmission electron microscopy(TEM)and EDS spectrogram.This paper studies Mo-C alloy as Schottky contact metal,where the atomic ratio of Mo-C alloy is 2:1.The results show that the Mo-C alloy 4H-SiC under high temperature annealing has a small ideality factor,and the ideality factor of annealing at 900?reaches 1.03.Combined with material characterization analysis,it can be considered that this structure greatly improves the inhomogeneity of the Schottky barrier.The breakdown voltage of Schottky diodes using the basic Si O₂ dielectric layer as the field plate dielectric can reach 1360V.This paper also studied the Schottky contacts of different proportions of Mo-C alloys.The two Mo-C alloy systems exhibit relatively uniform interface characteristics,with an ideality factor close to 1,and the barrier height does not fluctuate greatly with the annealing temperature,which has good electrical properties.It proves that the metal Mo-C alloy has the potential to form good Schottky contacts and has good high temperature annealing stability.