Electrical properties of high-k materials prepared by ALD
Atomic layer deposition has been recognized as a prospective, in several cases an appropriate, method for the fabrication of contemporary and advanced electronic devices - insulating layers in head gap devices,field effect transistors, three-dimensional dynamic random access memory structures. Attempts have been made to adopt several metal precursors in the deposition process of high-permittivity oxide thin films. Suitable chemical precursors have been searched among a list of compounds, such as metal halides, alkoxides, alkylamides, cyclopentadienyls. Accommodation of different precursors with the deposition process has resulted in a variety of physical and chemical properties, characterizing the resulting thin solid films. For instance, hafnium and zirconium alkylamides and cyclopentadienyls have been considered as promising precursor enabling the conformal atomic layer deposition. At the same time, some of these precursors suffer from the ability to decompose thermally, whereas other precursor produce films possessing significant crystallographic phase heterogeneity. The films grown in different processes show noticeable differences in the leakage current densities, conduction mechanisms, capacitance-voltage behaviour and defect densities. Some of these issues will be described in the present work.
Presentation: Invited at E-MRS Fall Meeting 2007, Symposium C, by Kaupo Kukli
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-11 10:36 Revised: 2009-06-07 00:44