Dresden 2014 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 19: Nitrides: Devices

HL 19.7: Talk

Monday, March 31, 2014, 16:30–16:45, POT 151

Surface passivation studies of AlInN/GaN based HEMTs grown on Si(111) by MOVPE — •Jonas Hennig, Aqdas Fariza, Hartmut Witte, Juergen Blaesing, Armin Dadgar, and Alois Krost — Institut of Experimental Physics, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany

GaN is a wide bandgap material and therefore a good candidate for building high electron mobility transistors (HEMTs) or switching devices with large breakdown voltages. Furthermore, the high electron mobility predestines this material system for high frequency applications that are needed in the telecommunication industry. The spontaneous polarization difference at the AlInN/GaN heterojunction results in a high carrier density of the two dimensional electron gas (2DEG) and therefore in a higher source drain current compared with well-established AlGaN/GaN HEMTs. Although this makes AlInN/GaN HEMTs promising candidates for the application mentioned above these devices suffer from large gate leakage. To reduce the leakage current different capping layers for surface passivation can be chosen. We will present a comparative study of GaN passivation as well as in-situ and ex-situ SiN capping layer and discuss the impact on the device performance. Structural analyses are carried out by XRD and AFM. The electrical characterization includes Hall-effect, C-V measurements and admittance spectroscopy.