Low-temperature field-effect and magnetotransport properties in a ZnO based heterostructure with atomic-layer-deposited gate dielectric

• 塚崎 敦

• Tsukazaki Atsushi

• 大友 明

• Ohtomo Akira

• 千葉 大地

• Chiba Daichi

• 大野 裕三

• Ohno Yuzo

• 大野 英男

• Ohno Hideo

• 川崎 雅司

• Kawasaki Masashi

Abstract

A top-gate field-effect device with atomic-layer-deposited Al₂O₃ dielectric was fabricated to investigate magnetotransport properties of two-dimensional electron gas (2DEG) at a semi-insulating ZnO-Mg_0.12Zn_0.88O double heterostructure grown by laser molecular-beam epitaxy. Hall mobility monotonically increased as the density of accumulated electrons increased. The highest mobility at 2 K was recorded to be 5000 cm² V-1 s^-1 at a 2DEG density of 1.2x10¹² cm^-2, which is comparable to the previously reported value for a metallic ZnO/Mg_0.2Zn_0.8O heterostructure. Insulator-to-metal transition was observed at a critical density of 6x10¹¹ cm^-2. The metallic-state channel exhibited Shubnikov-de Haas oscillations, demonstrating an electric-field tunable quantum device based on transparent oxide semiconductor.

Journal

• Applied Physics Letters

  Applied Physics Letters 93 (24), 2008-12

Keywords

• aluminium compounds, dielectric materials, electron density, Hall mobility, II-VI semiconductors, magnesium compounds, metal-insulator transition, molecular beam epitaxial growth, semiconductor heterojunctions, semiconductor-insulator boundaries, Shubnik

Details

• CRID: 1573668927584841600
• NII Article ID: 120006581945
• ISSN: 00036951
• Web Site: http://t2r2.star.titech.ac.jp/cgi-bin/publicationinfo.cgi?q_publication_content_number=CTT100609382
• Text Lang: en
• Data Source:
  • CiNii Articles