Electrical properties of n-GaN/p-SiC and n-AlGaN/p-SiC heterojunction diodes

B. Luo, Ji Hyun Kim, R. Mehandru, F. Ren, K. P. Lee, S. J. Pearton, A. Y. Polyakov, N. B. Smirnov, A. V. Govorkov, E. A. Kozhukhova, B. Tolmachevsky, A. V. Osinsky, P. E. Norris

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Properties of n-GaN/p-SiC and n-AlGaN/p-SiC heterojunctions prepared by HVPE on 4H SiC substrates were studied by means of C-V, C/G-T, C-f, I-V and DLTS. It is shown, in agreement with earlier publications, that the GaN/p-SiC HJ is staggered type II with ΔE c=-0.4 eV and ΔE v=0.6 eV. When changing GaN for AlGaN with Al mole fraction of x=0.25-0.3 the band alignment becomes normal type I with ΔE c=0.2 eV and ΔE v=0.6 eV. I-V characteristics of both heterojunctions bear evidence of strong tunneling via defect states, particularly centers with activation energy of 1.25 eV for GaN/4H SiC HJ. The tunneling was found to be more pronounced in the AlGaN/SiC HJs even though these HJs showed no evidence of formation of dark line defects at the interface, in contrast to GaN/SiC. DLTS measurements on both types of HJs revealed the presence of broad bands whose behavior is indicative of these bands being related to continuous states in the gap, most likely near the nitride/carbide interface.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsJ.E. Northrup, J. Neugebauer, D.C. Look, S.F. Chichibu, H. Riechert
Number of pages6
Publication statusPublished - 2002
Externally publishedYes
EventGaN and Related Alloys-2001 - Boston, MA, United States
Duration: 2001 Nov 262001 Nov 30


OtherGaN and Related Alloys-2001
CountryUnited States
CityBoston, MA


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Luo, B., Kim, J. H., Mehandru, R., Ren, F., Lee, K. P., Pearton, S. J., Polyakov, A. Y., Smirnov, N. B., Govorkov, A. V., Kozhukhova, E. A., Tolmachevsky, B., Osinsky, A. V., & Norris, P. E. (2002). Electrical properties of n-GaN/p-SiC and n-AlGaN/p-SiC heterojunction diodes. In J. E. Northrup, J. Neugebauer, D. C. Look, S. F. Chichibu, & H. Riechert (Eds.), Materials Research Society Symposium - Proceedings (Vol. 693, pp. 335-340)