Model, Prediction and Experimental Verification of Composition and Thickness in Continuous Spread Thin Film Combinatorial Libraries Grown by Pulsed Laser Deposition

Published

July 16, 2007

Author(s)

Nabil Bassim, Peter K. Schenck, Makoto Otani, Hiroyuki Oguchi

Abstract

Pulsed laser deposition (PLD) is a powerful technique for growing continuous spread thin film libraries of continuously varying composition as a function of position on a substrate. Continuous spread thin film libraries are grown by striking a ceramic target with short pulses of KrF laser light in a low-pressure oxygen background to deposit a film of monolayer thickness. The target is then exchanged for another target, the substrate is rotationally indexed to another position, and another monolayer film may be grown. This procedure is repeated a number of times so that the films are naturally mixed with respect to composition and thickness, both of which vary across the wafer. The thickness of each component that contributes to the films varies continuously and can be approximated as being proportional to a bimodal cosine power distribution, primarily due to the shape of the expanding material plume as it leaves the target, and its subsequent interaction with any background gas within the chamber. In order to design continuous spreads for the measurement of materials properties as a function of composition, it is important to measure, model and subsequently predict the variation of both the thickness and composition in the library. The thickness distribution of the deposition pattern may be changed as well by changing processing conditions during the growth, such as partial pressure of background gas within the chamber. In this study, we deposit ternary continuous spread thin film libraries from Al2O3, HfO2 and Y2O3 targets, at two different background pressures of O2: 1.3 and 13.3 Pa and compare our predictions to measured thickness and composition. We found a strong correlation between the two indicating that we are able to accurately

Citation

Review of Science Instruments

Volume

78

Issue

7

Pub Type

Journals

Keywords

combinatorial, compositional coverage, pulsed laser deposition

Citation

Bassim, N. , Schenck, P. , Otani, M. and Oguchi, H. (2007), Model, Prediction and Experimental Verification of Composition and Thickness in Continuous Spread Thin Film Combinatorial Libraries Grown by Pulsed Laser Deposition, Review of Science Instruments (Accessed May 6, 2024)