Analysis of current crowding in thin film contacts from exact field solution

作者：Zhang, Peng^*; Lau, Y. Y.; Gilgenbach, R. M.

来源：Journal of Physics D: Applied Physics , 2015, 48(47): 475501.

DOI：10.1088/0022-3727/48/47/475501

• electrical contact
• current crowding
• specific contact resistance
• spreading resistance
• joule heating

The paper presents a systematic evaluation of current crowding and spreading resistance in thin film contacts, based on the exact field solution that contains very large contrasts in dimensions and resistivity. It is found that current crowding becomes more severe as the interface specific contact resistivity decreases, the resistivity ratio of the contact electrode to the thin film decreases, or the thickness of either the contact or the thin film decreases. The current transfer length L-T from our exact field solution is compared to that of transmission line model (TLM), L-TLM = (rho(c)/rho(sh))(1/2), where rho(c) is the interface specific contact resistivity, and rho(sh) is the sheet resistance of the thin film under contact. It is found that, if rho(c) is small, L-T is bounded by the smaller of the two dimensions-thin film thickness and contact size. As rho(c) increases, L-T increases, but saturates at a constant value, determined by the smaller of the two dimensions-contact size and L-TLM. The total contact resistance is decomposed into three components: the interface resistance du

• 出版日期2015-12-2