Two-dimensional electron gas in Zn polar ZnMgO/ZnO heterostructures grown by radical source molecular beam epitaxy

H. Tampo, H. Shibata, K. Matsubara, A. Yamada, P. Fons, S. Niki, M. Yamagata, H. Kanie

Research output: Contribution to journalArticle

95 Citations (Scopus)

Abstract

A two-dimensional electron gas was observed in Zn polar ZnMgO/ZnO (ZnMgO on ZnO) heterostructures grown by radical source molecular beam epitaxy. The electron mobility of the ZnMgO/ZnO heterostructures dramatically increased with increasing Mg composition and the electron mobility (μ ∼ 250 cm 2/V s) at RT reached a value more than twice that of an undoped ZnO layer (μ ∼ 100 cm2/V s). The carrier concentration in turn reached values as high as ∼1 × 1013 cm-2 and remained nearly constant regardless of Mg composition. Strong confinement of electrons at the ZnMgO/ZnO interface was confirmed by C- V measurements with a concentration of over 4 × 1019 cm-3. Temperature-dependent Hall measurements of ZnMgO/ZnO heterostructures also exhibited properties associated with well defined heterostructures. The Hall mobility increased monotonically with decreasing temperature, reaching a value of 2750 cm2/V s at 4 K. Zn polar "ZnMgO on ZnO" structures are easy to adapt to a top-gate device. These results open new possibilities for high electron mobility transistors based upon ZnO-based materials.

Original languageEnglish
Article number132113
JournalApplied Physics Letters
Volume89
Issue number13
DOIs
Publication statusPublished - 2006 Oct 6
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Fingerprint Dive into the research topics of 'Two-dimensional electron gas in Zn polar ZnMgO/ZnO heterostructures grown by radical source molecular beam epitaxy'. Together they form a unique fingerprint.

  • Cite this