XPS and IPE analysis of HfO2 band alignment with high-mobility semiconductors

✍ Scribed by M. Perego; G. Seguini; M. Fanciulli

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 357 KB
• Volume: 11
• Category: Article
• ISSN: 1369-8001
• DOI: 10.1016/j.mssp.2008.10.008

✦ Synopsis

A detailed analysis of the band alignment between atomic-layer deposition (ALD)grown HfO 2 thin films and n-type Ge(1 0 0) substrate is presented. The valence band offset (VBO) is determined by X-ray photoelectron spectroscopy (XPS) after careful evaluation of the experimental data and accurate removal of the artefacts induced by differential charging phenomena occurring during XPS measurement. VBO values are 2.770.1 eV for all samples independent of the different growth conditions. A conduction band offset (CBO) of 2.070.1 eV and a band gap of 5.670.1 eV have been obtained by internal photoemission (IPE) and photoconductivity measurements, respectively. VBO and CBO values obtained by the different techniques are in excellent agreement within the experimental error.