AVS 47th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP32
Importance of Thermal Stress in a Thin Film Lipon Solid Electrolyte

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: F. Vereda, Tufts University
Authors: F. Vereda, Tufts University
R.B. Goldner, Tufts University
T. Haas, Tufts University
Correspondent: Click to Email
Because a near term goal of our research is to obtain optimal performance physically vapor-deposited LiCoO@sub 2@/Lipon/C thin film batteries (Lipon = lithium phosphorus oxynitrade), and due to the major importance of the electrolyte in any battery, we have recently been attempting to better understand the causes of electronic shorting that affects our Lipon electrolyte films. After studying the residual and temperature-dependent stress of these films and observing severe cracking after they had undergone a relatively large thermal transient (from 300 °C to room temperature), we adopted a model in which a thermal expansion coefficient mismatch between Lipon and our glass substrates accounts for the cracking and therefore the shorting. This model was also supported by the fact that Al films, which proved to act as a 'buffer layer' and stopped cracking of Lipon when glass/Al/Lipon structures were cooled from 300 °C to room temperature, were successfully used to produce short-free Al/Lipon/Al devices.