Application of atomic layer deposited Al2O3 as charge injection layer for high-permittivity dielectrics

被引：5

作者：

Hillmann, Stephan ^{[1
]}

Rachut, Karsten ^{[1
]}

Bayer, Thorsten J. M. ^{[1
]}

Li, Shunyi ^{[1
]}

Klein, Andreas ^{[1
]}

机构：

[1] Tech Univ Darmstadt, Inst Mat Sci, Div Surface Sci, D-64287 Darmstadt, Germany

来源：

SEMICONDUCTOR SCIENCE AND TECHNOLOGY | 2015年 / 30卷 / 02期

关键词：

(Ba; Sr)TiO3; charge transport; Al2O3; band alignment; LEAKAGE CURRENT; BAND-STRUCTURE; SPECTROSCOPY; INTERFACE; CAPACITOR; PHOTOEMISSION; MECHANISMS; ALIGNMENT;

D O I：

10.1088/0268-1242/30/2/024012

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

The current transport through (Ba,Sr)TiO3 (BST)/Al2O3 bilayer structures with Pt electrodes is studied using current-voltage measurements. Due to its low permittivity compared to BST the Al2O3 layer, which is deposited by atomic layer deposition (ALD), enables electron injection by tunneling at low thickness, such that transport becomes limited by the bulk conductivity of BST. A current rectification of up to 10(6) is observed at an Al2O3 thickness of 1.8 nm, indicating that hole transport does not contribute to the current. The measurements are complemented by the determination of the energy band alignment at the interface using photoelectron spectroscopy. A Fermi level pinning in the Al2O3 layer, which seems to be characteristic for ALD films, leads to a significant modification of the energy band alignment. This pinning does not prohibit electron injection, which relies on the potential drop across the Al2O3 layer.

引用

页数：7

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