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

• Published in: Thin solid films Vol. 519; no. 9; pp. 2811 - 2816
• Main Authors: Nguyen, N.V., Kirillov, O.A., Suehle, J.S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 28-02-2011; Elsevier
• Subjects: Alignment; Band alignment; Band offsets; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectrics; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Ellipsometry; Exact sciences and technology; Gates; High-k dielectric; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Interface; Internal photoemission; Metal gate; Metal oxide semiconductors; MOS; Optical instruments, equipment and techniques; Physics; Polarimeters and ellipsometers; Semiconductors; Silicon substrates; Spectroscopic ellipsometry; Spectroscopy; Surface and interface electron states; Surface states, band structure, electron density of states; MOS; Spectroscopic ellipsometry; Band alignment; High-k dielectric; Internal photoemission; Band offsets; Metal gate; Interface; Valence bands; Transport properties; Electronic conductivity; Semiconductor devices; Tantalum nitride; Hafnium oxide; Interface properties; Photoemission; Gallium tellurides; Internal structure; Silicon; Band offset; Aluminium oxide; Conduction bands; Electronic properties; Semiconductor materials; MOS structure; Indium arsenides; Interfaces; Electronic structure; Reviews; Fermi level; Silicon oxides; Metrology; Logic gates; High k dielectric; Gates; Heterostructures
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.11.080

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 / InxGa1−xAs substrate.