Band alignment of metal-oxide-semiconductor structure by internal photoemission spectroscopy and spectroscopic ellipsometry

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• 作者：N.V. Nguyen ; ^a ; ^{nhan.nguyen@nist.gov} ; O.A. Kirillov^a ; J.S. Suehle^a
• 关键词：Internal photoemission ; Spectroscopic ellipsometry ; High-k dielectric ; Metal gate ; MOS ; Band offsets ; Band alignment ; Interface
• 刊名：Thin Solid Films
• 出版年：2011
• 出版时间：28 February 2011
• 年：2011
• 卷：519
• 期：9
• 页码：2811-2816
• 全文大小：873 K

文摘

In this paper, we will provide an overview of the internal photoemission (IPE) and the significance of this technique when combined with spectroscopic ellipsometry (SE) to investigate the interfacial electronic properties of heterostructures. In particular, the main interest is focused on the electron transport mechanism and properties at and near the interface of the technologically important metal-oxide-semiconductor (MOS) devices. Not until recently, IPE and SE have become important metrology tools in band offset characterization for the MOS materials. The most common and straightforward application of IPE and SE is to determine how the Fermi level of the metal, and the conduction and valence bands of the semiconductor align with those of the oxide of the MOS structure. For demonstration, we will present the results recently obtained on a set of MOS devices consisting of metal gate / high-k dielectric stack / Si and III–V high mobility substrate. The examples include [TaN/TaSiN] metal gate / [HfO₂/SiO₂] dielectric stack / Si substrate and Al metal gate / Al₂O₃ dielectric / In_xGa_1 − xAs substrate.