Soft Recovery Characteristics Research Articles

Study on the Characteristics of FSRD with a Corrugated Anode and p+ Adjustment Region at Cathode

The reverse recovery characteristic of the power diode will directly affect the reliability of the inverter application. In order to improve the reverse recovery characteristics of the fast and soft recovery diode (FSRD), a new FSRD structure with Corrugated Anode and P+ adjusting Cathode (CA-PC-FSRD) is studied by the Sentaurus-TCAD simulator and compared with the characteristics of conventional FSRD. The influence of key parameters, such as the height and width of anode corrugation and the width of the p+ adjusting region at the cathode, on the characteristics are discussed. Simulation results show that the CA-PC-FSRD has excellent soft recovery characteristics compared with the conventional FSRD at the same voltage level.

Effects of p and n pillar widths on electrical characteristicsof super junction SiGe power diodes

By combining merits of both SJ structure and SiGe material, a novel super junction (SJ) SiGe power diode is presented. The two important characteristics of SJ SiGe diode are its columnar structure of alternating p/n pillars substituting n- base region of conventional Si p+n-n+ diode and its far thinner strained SiGe p+ layer, which can overcome the drawbacks of conventional Si power switching diodes, such as when the reverse blocking voltage is higher, the forward voltage drop is larger and the reverse recovery time becomes longer. For the SJ SiGe diode with 20% Ge content, the following conclusions can be obtained compared with comparable conventional Si power diodes: the breakdown voltages increase by 1.6 times, the forward voltage drop is reduced by 60 mV (at a current density of 10 A/cm2) and the softness factor S increases by 2 times. Though the reverse recovery time is shortened slightly, the peak reverse current density decreases by 17% and the soft recovery characteristics is improved notedly. The key parameters of the p and n pillar widths have imporant effects on the forward conduction characteristic, reverse blocking characteristic and reverse recovery characteristic of SJ SiGe power diode. The smaller the pillar width becomes, the higher the breakdown voltage is and the lower the reverse leakage current is, whereas the forward voltage drop increases slightly. The pillar width has no obviously monotonic effect on the reverse recovery characteristic. If the width is too small, the soft reverse recovery characteristic is degenerated. To optimize the parameter of pillar width, we can obtain excellent SJ SiGe diode with fast recovery speed, high breakdown voltage and low forward drop at the same time.

A novel low on-resistance Schottky-barrier diode with p-buried floating layer structure

A novel low on-resistance Schottky-barrier diode (SBD) structure with a p-buried floating layer is demonstrated by fabricating 300-V SBDs using a buried epitaxial growth technique. The fabricated SBDs realize a 50% reduction of chip area and show a possibility of higher breakdown voltage SBD of over 100 V. In addition, both the low on-resistance and the soft-recovery characteristics can be realized by the p-buried floating layer structure. The demonstrated structure is very attractive for reduction of power dissipation without electromagnetic interference noise increase.