Electrical and structural properties of Ti/Al-based contacts on AlGaN/GaN heterostructures with different quality

被引：4

作者：

Greco, Giuseppe ^{[1
]}

Iucolano, Ferdinando ^{[2
]}

Bongiorno, Corrado ^{[1
]}

Di Franco, Salvatore ^{[1
]}

Lo Nigro, Raffaella ^{[1
]}

Giannazzo, Filippo ^{[1
]}

Prystawko, Pawel ^{[3
,4
]}

Kruszewski, Piotr ^{[3
,4
]}

Krysko, Marcin ^{[3
,4
]}

Grzanka, Ewa ^{[3
,4
]}

Leszczynski, Michal ^{[3
,4
]}

Tudisco, Cristina ^{[5
]}

Condorelli, Guglielmo Guido ^{[5
]}

Roccaforte, Fabrizio ^{[1
]}

机构：

[1] CNR IMM, I-95121 Catania, Italy

[2] STMicroelect, I-95121 Catania, Italy

[3] Inst High Pressure Phys PAS, PL-01142 Warsaw, Poland

[4] TopPGaN Ltd, PL-01142 Warsaw, Poland

[5] Univ Catania, Dipartimento Sci Chim, I-95125 Catania, Italy

来源：

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE | 2015年 / 212卷 / 05期

关键词：

AlGaN; GaN; ohmic contacts; titanium; aluminimum; defects; VACANCY-RELATED DEFECTS; OHMIC CONTACTS; SURFACE; TI; NITROGEN; CONDUCTIVITY; DISLOCATIONS; TRANSISTORS; BUFFER;

D O I：

10.1002/pssa.201431636

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

In this work, the electrical and structural properties of Ti/Al contacts on AlGaN/GaN heterostructures with a different crystalline quality were investigated. In particular, the sample with a lower defects density required a higher temperature (800 degrees C) to obtain Ohmic contacts, while the more defective sample showed Ohmic behaviour at lower annealing temperature (500 degrees C). The susceptibility to oxidation of the metal stack upon annealing has been monitored by chemical analyses. Moreover, the temperature dependence of the contact resistance of the Ti/Al annealed contacts revealed that the interface current transport mechanism depends on the material quality. These results were attributed to the presence of V-shaped defect close to the surface of the AlGaN barrier layer. A nanoscale electrical analysis demonstrated a preferential current conduction through these defects, which indeed plays a relevant role for the formation of the Ohmic contact.

引用

页码：1091 / 1098

页数：8

共 48 条

[1] Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures [J].