ON THE ASTM ELECTROMIGRATION TEST STRUCTURE APPLIED TO AL-1-PERCENT-SI TIN/TI BAMBOO METAL LINES/

The applicability of NIST-ASTM electromigration test patterns when use d to test 'bamboo' metal lines is discussed. Wafer level tests on pass ivated and non-passivated samples employing the Al-1%/Si/TiN/Ti metall ization scheme were performed. Straight metal lines 1000 mum long and 0.9 mum or 1.4 mum wide were tested at two different current densities , j = 3 MA/cm2 and j = 4.5 MA/cm2, at constant stress temperature (T = 230-degrees-C). The failures mainly occurred in the end-segment areas and hindered the evaluation of the electromigration resistance of the 'bamboo' test lines. In order to avoid this problems, completely diff erent test patterns based on different approaches must be designed.