Development Of Silicon-based Power JBS/MPS Schottky Rectifier

In order to expand the market of Schottky rectifier in high-voltage and high-power devices field, the new Schottky rectifiers(which is junction barrier Schottky rectifier or mixed pin/Schottky Rectifier, referred to as JBS/MPS rectifier) structure was proposed. The two kinds of new Schottky rectifiers, respectively, p-n junction or pin and Schottky structure were integrated on a single chip. This kind of technology just increases one step photolithography in the process, which greatly reduces their production costs and also makes it possible to fabricate a new type Schottky rectifier with high breakdown voltage, low leakage current, low threshold voltage, and also with good anti-surge ability and a shorter recovery time response.According indicators of 10-20A/600 V junction barrier Schottky diode development project, beginning with the basic theory of the silicon JBS/MPS rectifier, then was discussed in detail, calculated, and simulated, which c ould determine the simulation parameters and the layout of silicon JBS/MPS rectifier. Then the characteristics of the silicon JBS/MPS rectifier are discussed, specifically as follows:(1) According to the theory of the Schottky, the essential theory about JBS/MPS rectifiers and the relationship between the device’s parameters and its electrical characteristics were deduced. It was found that the influence from the conductivity modulation effect of JBS/MPS rectifier was still very large;(2) Through taping out experiments, the expent of active region structure, the thickness of exidation layer, p+ junction doping comentration and metal barrier to the properties of JBS/MPS rectifier was studied in detail. Honeycomb structure in active region was presented in order to improve the electrical characteristics of JBS/MPS rectifier and the consistency of silicon wafers in a greater extent;(3) Through the theoretical calculation of JBS/MPS rectifier and simulation using Silvaco software, finally multi-channel limiting ring terminal structure might increase the breakdown voltage of the device to a certain extent, and the use of TEOS-BPSG on MPS rectifier, polycrystalline silicon, SiO2 terminal structure multilayer passivation layer and the field limiting ring combination.To sum up the work, according to our improved layout(MPS Version) flow sheets, packaging and testing, and studied their electrical properties, temperature characteristics, the results showed that: MPS rectifier electrical properties produced excellent consistency. The case is not more than 1.2V forward voltage drop of the forward current reaches 10A; in the case of forward voltage drop is not greater than 1.5V, the forward current of 20A; the reverse leakage current is less than 100μA case, anti the breakdown voltage reaches 600 V above; with increasing ambient temperature, MPS rectifier forward voltage drop with increasing temperature and decreasing, while the reverse breakdown voltage will continue to grow.