AVS 45th International Symposium
    Electronic Materials and Processing Division Thursday Sessions
       Session EM+PS-ThM

Paper EM+PS-ThM3
Scanning Capacitance Imaging for Evaluation of High-k Dielectric Oxide Materials

Thursday, November 5, 1998, 9:00 am, Room 314/315

Session: Processing of High K Dielectrics for DRAMs
Presenter: H.C. Galloway, Southwest Texas State University
Authors: Y. Yamaguchi, Southwest Texas State University
K.P. Wiederhold, Southwest Texas State University
B.D. White, Southwest Texas State University
N.E. Wittry, Southwest Texas State University
H.C. Galloway, Southwest Texas State University
Correspondent: Click to Email
We have used scanning capacitance imaging to measure the dielectric properties of oxide materials such as BST which have large dielectric constants (high-k). These materials are of interest as potential replacements for the dielectric in memory devices due to their increased capacitance per unit area. Several scanning capacitance methods have been developed using modified atomic force microscopes and they are actively used to measure quantities such as the thickness of SiO@sub 2@ layers or the doping levels across a p-n junction. We will discuss how this technique can be used as a diagnostic tool when applied to the high-k oxides. First, the measurement of the dielectric properties on a local scale may help to identify the causes of failure modes in materials. As an example, we will report on local variations of the dielectric constant observed in films of BST grown by RF planar magnetron sputtering. Second, we have used scanning capacitance to evaluate films of novel oxide materials grown by Dual Ion Beam Sputtering.@footnote 1@ The advantage of Scanning Capacitance Microscopy is that the relative merits of different growth conditions can be rapidly assessed and compared to each other or to a reference standard. This allows us to investigate new materials or deposition conditions without having to form complete devices for analysis. By identifying the most promising growth conditions that yield high dielectric constants, uniform films, and low leakage currents we can speed up the process of testing new growth methods and materials. @FootnoteText@ @footnote 1@P. Perera, R. Selestino, and C.J. Gutierrez, Department of Physics, Southwest Texas State University