PERGAMON MicroelectronicsReliability39 (1999) 991-996 MICROELECTRONICS RELIABILITY www.elsevier.com/locate/microrel TIVA and SEI developments for enhanced front and backside interconnection failure analysis E.I. Cole Jr., P. Tangyunyong, D.A. Benson, D.L. Barton Sandia National Laboratories, Electronics Quality~Reliability Center, 1515 Eubank SE, MS 1081, Albuquerque, NM87185-1081, USA Abstract Thermally-Induced Voltage Alteration (TIVA) and Seebeck Effect Imaging (SEI) are newly developed techniques for localizing shorted and open conductors from the front and backside of an IC. Recent improvements have greatly increased the sensitivity of the TIVA/SEI system, reduced the acquisition times by more than 20X, and localized previously unobserved defects. The system improvements, non-linear response of IC defects to heating, modeling of laser heating and examples using the improved system are presented. © 1999 Elsevier Science Ltd. All rights reserved. 1. Introduction Open and short-circuited interconnections are major IC yield and reliability problems and will increase in importance as the number of interconnection levels, reduction in pitch, and length of interconnections increase. The increasing number of levels of metal interconnection and flip- chip packaging have further complicated defect localization. The TIVA and SEI techniques were recently developed [1] to address these problems, with TIVA for localizing shorted interconnections and SEI for localizing open conductors. Both of the techniques take advantage of the interactions between an infrared laser (~=1.3 p m) and the defect, making them applicable from both the front and backside of an IC. Since the initial development of TIVA and SEI, efforts have centered on improving the sensitivity of the techniques. Recent system modifications have greatly increased the defect detection sensitivity of both techniques, resulting in faster failure localization and diagnosis. System improvements and imaging examples illustrating the utility of the enhanced TIVA and SEI techniques are described in sections 3 and 5. Modeling results showing the thermal distribution and response of static and dynamic laser heating are also discussed. 2. SEI and TIVA Imaging The SEI and TIVA techniques employ the constant current biasing method used in Charge- Induced Voltage Alteration (CIVA) [2] and Light- Induced Voltage Alteration (LIVA) [3]. The constant current biasing approach provides an extremely sensitive method for detection of subtle changes in the IC power demand. In SEI, localized heating of an open conductor generates a thermal gradient that produces a voltage gradient. This behavior is known as the Seebeck Effect and refers to the work of Thomas Seebeck [4]. The voltage gradients are on the order of ~tV/K [5]. For IC analysis, the effect has been demonstrated as a 0026-2714/99/$ - see front matter. © 1999 Elsevier ScienceLtd. All rights reserved. PII: S0026-2714(99)00136-5