AVS 52nd International Symposium
    Electronic Materials and Processing Tuesday Sessions
       Session EM2-TuM

Paper EM2-TuM9
Atomic Layer Deposition and Characterization of Hafnium and Aluminum Oxides and Hafnium Aluminates on Silicon

Tuesday, November 1, 2005, 11:00 am, Room 312

Session: High-k Dielectric Characterization
Presenter: R.R. Katamreddy, University of Illinois at Chicago
Authors: R.R. Katamreddy, University of Illinois at Chicago
A. Deshpande, University of Illinois at Chicago
R. Inman, American Air Liquide
A. Soulet, American Air Liquide
G. Jursich, American Air Liquide
C.G. Takoudis, University of Illinois at Chicago
Correspondent: Click to Email
In future minimization of transistor devices, alternative high dielectric constant materials are needed to replace SiO@sub 2@ and its first-generation replacement material- silicon oxy-nitride. Among the diverse number of possible candidates, HfO@sub 2@ and Al@sub 2@O@sub 3@ films are currently among the most promising replacement materials. Each of these materials has different advantageous and disadvantageous properties for the gate dielectric application. So a more optimal film may be a compositional mixture or nanolaminated structure of these two materials. In this study, the two oxide films are investigated individually on silicon in order to further investigate more complex combinations of the two metal oxides. Ultra-thin hafnium oxide and aluminum oxide films are grown on precleaned silicon substrate having approximately 10 Å residual oxide thickness. The deposition takes place in an ALD reactor using tetrakis(diethylamino)hafnium and tris(diethylamino)aluminum@footnote 1@ precursors respectively. The oxidizing co-reactant is water. After deposition, some of the resulting high-k films are annealed at 600 - 1000°C. Both deposition film and its interfacial region of annealed and non-annealed sample substrates are characterized using Fourier Transformed infrared spectroscopy, X-ray Photoelectron Spectroscopy, Scanning Transmission Electron Microscopy (STEM) and Electron Energy-Loss Spectroscopy in STEM. Our studies indicate that the as-deposited HfO@sub 2@ film is amorphous and there is no indication of silicate formation at the interface; upon annealing of these films, electron microscopy measurements reveal a novel interesting sequence of interfacial transformations as the temperature increases. Similar measurements on Al@sub 2@O@sub 3@ films will be discussed. Preliminary results on nanolaminate deposition of Al@sub 2@O@sub 3@ and HfO@sub 2@ films will also be presented. @FootnoteText@ @footnote 1@ US Patent Application Number 20050003662 A1 filed in May, 2004.