In:
Acta Physica Sinica, Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences, Vol. 70, No. 3 ( 2021), p. 037102-
Kurzfassung:
“Bipolar degradation” phenomenon has severely impeded the development of 4H-SiC bipolar devices. Their defect mechanism is the expansion of Shockley-type stacking faults from basal plane dislocations under the condition of electron-hole recombination. To suppress the “bipolar degradation” phenomenon, not only do the basal plane dislocations in the 4H-SiC drift layer need eliminating, but also a recombination-enhancing buffer layer is required to prevent the minority carriers of holes from reaching the epilayer/substrate interface where high-density basal plane dislocation segments exist. In this paper, Ti and N co-doped 4H-SiC buffer layers are grown to further shorten the minority carrier lifetime. Firstly, the dependence of Ti doping concentration on TiCl〈sub〉4〈/sub〉 flow rate in 4H-SiC epilayers is determined by using single-dilution gas line and double-dilution gas line. Then the p〈sup〉+〈/sup〉 layer and p〈sup〉++〈/sup〉 layer in PiN diode are obtained by aluminum ion implantation at room temperature and 500 ℃ followed by high temperature activation annealing. Finally, 4H-SiC PiN diodes with a Ti, N co-doped buffer layer are fabricated and tested with a forward current density of 100 A/cm〈sup〉2〈/sup〉 for 10 min. Comparing with the PiN diodes without a buffer layer and with a buffer layer only doped with high concentration of nitrogen, the forward voltage drop stability of those diodes with a 2 μm-thick Ti, N co-doped buffer layer (Ti: 3.70 × 10〈sup〉15〈/sup〉 cm〈sup〉–3〈/sup〉 and N: 1.01 × 10〈sup〉19〈/sup〉 cm〈sup〉–3〈/sup〉) is greatly improved.
Materialart:
Online-Ressource
ISSN:
1000-3290
,
1000-3290
DOI:
10.7498/aps.70.20200921
Sprache:
Unbekannt
Verlag:
Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences
Publikationsdatum:
2021
