The Use of Apertures to Create Discrete Combinatorial Libraries Using Pulsed Laser Deposition

 

 

Nabil D. Bassim1*, P. K. Schenck1, M. L. Green**1, E. U. Donev2, L. C. Feldman2

 

1National Institute of Standards & Technology, Gaithersburg, MD, 20899

2Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37235

 

 

We employ a natural spread library technique pulsed laser deposition (PLD) which exploits the fact that the film growth rate is uneven and takes on a 2-dimenstional cosn thickness distribution in order to grow composition-spread thin films. In PLD, however, there are many processing parameters, besides composition, that influence film properties which may be studied such as substrate-target distance, background reactive gas pressure, laser energy and substrate temperature. By introducing an diameter circular aperture over a 3 wafer and rotating the substrate while changing conditions during the PLD process, these parameters may be studied as a discrete library as a function of processing conditions. We demonstrate the use of the aperture technique to systematically study the effects of oxygen partial pressure on the stoichiometry and growth rate of VOx, using Rutherford back-scattering (RBS). In another example, we discuss the effect of growth temperature on TiO2 films. We show here that we have considerable combinatorial control of other processing variables besides composition in our PLD combi system. These may be used to systematically study film growth and properties.

 

 

 

*Post-doctoral fellow

Nabil Bassim

Ceramics Division

Materials Science & Engineering Laboratory

Building 223, A245, Stop 8529, 975-8622 (p), 975-5334 (f), nabil.bassim@nist.gov

 

** Mentor Martin L. Green

 

Materials Science Specialty

 

Not a member of Sigma Xi.