电迁徙参数的电流斜坡动态测试

Measurement of Electromigration Parameter Under Current-Ramp Stress

采用电流斜坡法测试了４种不同金属化样品，其ｎ值分别为：２．２９（Ａｌ－Ｓｉ合金膜），１．２５（Ａｌ－Ｓｉ－Ｃｕ合金膜），１．２８（Ａｌ－Ｓｉ／Ｔｉ双层金属化），１．２３（Ａｌ／ＴｉＷＴｉ／Ａｌ多层金属化）．结果表明，ｎ值与材料有关，电迁徙阻力越高ｎ值越小，与ＢＬＡＣＫ方程相符。同时，考察了不同温度和不同电流上升斜率对ｎ值测量结果的影响，试验表明，在相当宽的温度范围和测试时间内获得的ｎ值一致性很好。

The measurement of current density exponent (n) is an extremely important parameter used for evaluating the lifetime of metallization in microelectronic devices. A new dynamic current-ramp method was developed to test the exponent n. It improved the accuracy and reduced test time by one or two orders of magnitude, comparing with the MTF method. The n four samples were measured under continuous DC, they were 2.29 (Al-Si alloy), 1.25 (Al-Si-Cu alloy), 1.28 (Al-Si/Ti two-level metallization) and 1.23 (Al-Si/TiWTi/AI-Si multilevel ), respectively. These results proved that the values of n are dependent on materials and well agreed with that of the black equation. The exponent n was also studied under different test temperature and current-ramping slope.It is independent of temperatureand current-ramping slope in a wide range.