Materials Science in Semiconductor Processing 9 (2006) 1055–1060 Photoelectron spectroscopy (XPS) and photoelectron diffraction (XPD) studies on the system hafnium silicide and hafnium oxide on Si(1 0 0) D. Weier a,b,Ã , C. Flu¨chter a,b , A. de Siervo c , M. Schu¨rmann a , S. Dreiner a , U. Berges a,b , M.F. Carazzolle d , A. Pancotti d , R. Landers c,d , G.G. Kleiman d , C. Westphal a,b a Institut of Physics, University Dortmund, Otto-Hahn-Str.4, D 44221 Dortmund, Germany b DELTA, University Dortmund, Maria-Goeppert-Mayer-Str. 2, D 44227 Dortmund, Germany c Laborato ´rio Nacional de Luz Sincrotron, C.P. 6192, 13084-971 Campinas, SP, Brazil d Instituto de Fisica, Universidade Estadual de Campinas, C.P. 6165, 13083-970 Campinas, SP, Brazil Available online 9 November 2006 Abstract Continuous down-scaling of silicon based transistors results in device lengths of less than 100 nm. This requires a reduction of the gate dielectric thickness to less than 15A ˚ which is not possible for SiO 2 due to an increasing leakage current. One of the most promising candidates for a replacement material for the gate dielectric is HfO 2 [Wilk GD, Wallace RM, Anthony JM. J Appl Phys 2001; 89:5243]. In this work we applied X-ray photoelectron spectroscopy (XPS) and photoelectron diffraction measurements in order to study the interface of hafnium oxide to Si(1 0 0). The high resolution measurements were performed with synchrotron radiation at beamlines 5 and 11 at DELTA (Dortmund). For the first time, photoelectron diffraction patterns for this system were recorded. The spectral resolution allowed to separate different spectral components. The preparation of hafnium oxide films on Si(1 0 0) was performed by evaporation of hafnium at a partial oxygen background pressure of 1  10 8 mbar. Three different spectral components were observed in the hafnium 4f photoemission signal by high resolution XPS. The photoelectron signals with binding energies shift of 3.1 and 1.2 eV with respect to signal of hafnium silicide were assigned to hafnium dioxide and hafnium silicate, respectively. The corresponding high-resolution diffraction patterns result from different local environments for each component. The experimental patterns are compared with simulations for a model structure of hafnium silicide. r 2006 Elsevier Ltd. All rights reserved. Keywords: Photoelectron diffraction; Hafnium oxide; High-k 1. Introduction Within the last three decades mainly SiO 2 was used as a gate dielectric in the silicon based CMOS (complementary-metalOxide-semiconductors) tech- nology, and, due to the fact that integrated circuits ARTICLE IN PRESS 1369-8001/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.mssp.2006.10.023 Ã Corresponding author. E-mail address: daniel.weier@uni-dortmund.de (D. Weier).