GaN FP-HEMTs中击穿电压与电流崩塌的关系

Relation between breakdown voltage and current collapse in GaN FP-HEMTs

研究了钝化在抑制电流崩塌的同时,会引起HEMT器件击穿电压的下降.而采用场板结构的AlGaN/GaN场板HEMT器件(FP-HEMT)的击穿电压从46V提高到了148V,表明了场板对提高击穿电压有显著作用(3倍以上).接着,比较了FP-HEMT器件与常规HEMT器件,钝化后HEMT器件在应力前后的电流崩塌程度,得出了采用场板结构比之钝化对器件抑制电流崩塌有更明显作用的结论.从理论上和实验上都表明,采用场板结构能够很好解决提高击穿电压与抑制电流崩塌之间的矛盾.

Passivation is generally used to suppress the current collapse, however, it also cause the decrease in breakdown voltage. By incorporating a field plate, the breakdown voltage was enhances from 46 to 148 V as tested using the drain current inject technology （DCIT）, which indicates that the field plate can increase the breakdown voltage remarkablely. Then, comparisons between the degrees of current collapse in the conventional HEMTs, the HEMTs after passivation and FP-HEMTs indicate that the field plate performs better in suppressing current collapse than passivation. It is conclusded that adopting the field plate structure is a good solution to the problem of incresing the breakdown voltage and at the same time suppressing the current collapse in GaN HEMTs.