United Microelectronics Corp.

Donald Cheng

Kuan-Yu Fu

Sheng-Hsing Yang

Mu-Chun Wang

Chuan H Liu

A method of testing EM lifetime has following steps. First, a pre-characterizing step is performed to obtain parameters such as T (the critical temperature,), Wc (the critical line width), Q (the activation energy of grain boundary diffusion) and Q (the activation energy of lattice diffusion) of a metal prior to the use of the test methodology for a new technology. Next, whether a real line width (W) of the metal is narrower or wider than W is determined. For the narrower line widths, the diffusion mechanism is dominated by the Lattice diffusion only and corresponds to single activation energy (Q ). A WLR isothermal test with a relatively high temperature, such as 400&deg; C., can be implemented to reduce the test time to as short as a few seconds. The EM lifetime (t ) under normal operating condition can be directly obtained by conversion from T to T by using Q .

Method of testing electromigration lifetime

A method for testing the reliability of a dielectric thin film. An exponential current ramp test is performed with a delay time to test the dielectric thin film. An exponential current ramp charge-to-breakdown distribution, which is represented by cumulative distribution failure percentage, is obtained. An exponential current ramp charge-to-breakdown at a cumulative distribution failure percentage is calculated. An exponential current ramp constant and a constant current stress constant at the cumulative distribution failure percentage are calculated. A constant current stress charge-to-breakdown at the cumulative distribution failure percentage is calculated by using a specified current density and the constant current stress constant at the cumulative distribution failure percentage. The constant current stress charge-to-breakdown at the cumulative distribution failure percentage is compared to a specified constant current stress charge-to-breakdown to determine the reliability of the dielectric thin film.

Growing community of inventors

Hsinchu, Taiwan

Donald Cheng