AVS 47th International Symposium
    MEMS Thursday Sessions
       Session MM-ThA

Paper MM-ThA5
Deposition of Highly Oriented LiCoO@sub 2@ Thin Films for Use as Cathodes in Thin Film Batteries

Thursday, October 5, 2000, 3:20 pm, Room 309

Session: Material Science of MEMS
Presenter: J.A. Ruffner, Sandia National Laboratories
Authors: J.A. Ruffner, Sandia National Laboratories
T.J. Boyle, Sandia National Laboratories
D. Ingersoll, Sandia National Laboratories
K.P. Peters, Sandia National Laboratories
M.A. Rodriguez, Sandia National Laboratories
J. Liang, Sandia National Laboratories
Correspondent: Click to Email
Presently micro-and meso-machines (MEMS) are powered by sources that are large in comparison to the actual MEMS devices. Development of small-scale power sources is critical if these devices are to reach their full usefulness. A prototype all-ceramic thin film battery that consists of a LiCoO@sub 2@ cathode, surface modified silica film composite electrolyte, and SnO@sub 2@ anode is presently under development at Sandia National Labs. Deposition of well-oriented, crystalline LiCoO@sub 2@ thin film cathodes is a critical step to achieve the highest capacities possible for these batteries. LiCoO@sub 2@ thin films deposited at ambient temperature using rf sputtering are generally amorphous in their as-deposited state. Post deposition annealing at temperatures > 300 °C results in melting and subsequent crystallization.@footnote 1@ However, it may be possible to promote crystallinity in the desired orientation [(101), (100) or (104) planes parallel to the substrate] by using a substrate or appropriate seed layer which is epitaxially matched to the desired LiCoO@sub 2@ orientation. Single-crystal metal substrates, such as Au (110), Re (100), or Ti (100), have lattices that are well-matched to LiCoO@sub 2@ lattices. However, these substrates are expensive and, in the case of Ti, readily oxidized. Instead, we deposited thin films of these metals as seed layers on more readily available single-crystal dielectric substrates (i.e. quartz) in order to test their effectiveness in promoting crystallization of subsequently deposited LiCoO@sub 2@ thin films in the desired orientation. We report on the orientation and properties of LiCoO@sub 2@ thin films deposited using rf sputter deposition versus solution chemistry. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000. @FootnoteText@ @footnote 1@ P. da Fonseca et al., J. Power Sources (1999), 81-82, 575-580.