MOCVD of Hafnium Silicate Films Obtained from a Single-Source Precusor on Silicon and Germanium for Gate-Dielectric Applications

Lemberger M, Schön F, Dirnecker T, Jank M, Frey L, Ryssel H, Paskaleva A, Zürcher S, Bauer A (2007)

Publication Type: Journal article

Publication year: 2007

Journal

Chemical Vapor Deposition Wiley-VCH Verlag

Publisher: Wiley-VCH Verlag

Book Volume: 13

Pages Range: 105-111

Journal Issue: 2-3

DOI: 10.1002/cvde.200606511

Abstract

In this work, hafnium silicate layers on Si and Ge wafers for gate dielectric application in metal-oxide-semiconductor devices are investigated. Films are deposited by metal-organic (MO)CVD using the single-source precursor Hf(acac)2(OSi^tBuMe2)2. This precursor exhibits good properties in terms of hydrolysis stability, volatility, and deposition. However, precursor decomposition is affected by surface conditions. Films deposited on Si wafers reveal high C contamination (up to 20 at %) and low Si content (up to 20 at%). In contrast, for film deposition on Ge wafers, no C contamination can be detected and Si incorporation is delayed until after about 15 nm HfO2 dielectric growth. Post-deposition rapid thermal annealing in an O2 atmosphere causes crystallization of deposited films, Si and Ge redistribution in the dielectric, respectively, and interfacial layer growth. However, oxygen annealing was also found to reduce effective oxide thickness (EOT) significantly compared to as-deposited films, which is attributed to crystallization effects. However, scaling of EOT is limited by that interfacial layer growth. Leakage currents are mainly caused by trap-related conduction mechanisms. Energy levels of involved traps decrease with increasing crystallization and/or Hf content, and values of 0.5 eV and 1 eV related to Hf and Si bonds, respectively, are obtained. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.

Authors with CRIS profile

Tobias Dirnecker Lehrstuhl für Elektronische Bauelemente Michael Jank Lehrstuhl für Elektronische Bauelemente Lothar Frey Lehrstuhl für Elektronische Bauelemente

How to cite

APA:

Lemberger, M., Schön, F., Dirnecker, T., Jank, M., Frey, L., Ryssel, H.,... Bauer, A. (2007). MOCVD of Hafnium Silicate Films Obtained from a Single-Source Precusor on Silicon and Germanium for Gate-Dielectric Applications. Chemical Vapor Deposition, 13(2-3), 105-111. https://dx.doi.org/10.1002/cvde.200606511

MLA:

Lemberger, Martin, et al. "MOCVD of Hafnium Silicate Films Obtained from a Single-Source Precusor on Silicon and Germanium for Gate-Dielectric Applications." Chemical Vapor Deposition 13.2-3 (2007): 105-111.

BibTeX: Download