Compliance Compensation Analysis of Micromechanical Testers Integrated With Acoustic Emission Sensors

Abstract

A damage test method is developed to characterize the damage behavior of the bond pad stack structure of an integrated circuit chip. The test method uses a micromechanical test machine (MTM) for an indentation test and an acoustic emission sensor for the bond pad stack crack or damage detection. This would bring about the need for considering the effects of the sensor and others on the total compliance. Previous works have not considered or were unable to consider these effects, and a linear elastic behavior is usually assumed for the load frame compliance compensation. As a result, this may provide a significant error in calculating the indentation displacement and damage energy. In this paper, a detailed compliance test, analysis, and compensation technique of a damage test system are presented, where the nonlinear elastic behavior effect is considered. It is found that the compliance test is independent of the loading rate but dependent on the maximum load applied, where a nonlinear elastic behavior of the system compliance is observed at a higher indentation load. In order to avoid erroneous calculation in the indentation displacement and damage energy of the evaluated specimen in the damage test, a nonlinear elastic behavior of the system compliance has to be considered. This could be essential for any MTM integrated with external sensing elements and fixtures.

Indentation damage evaluation on metal-coated thin-films stacked structure

“…The indented surface of the top metallization layer was usually removed by wet chemical etchant (i.e., mixture of acids) to expose the dielectric SiO 2 or Si 3 N 4 layer, and followed by rinsing the specimens with deionized water. 41 This delayering failure analysis technique only revealed the bulk material cracking or damage on the surface of the dielectric layer. To examine for any interfacial crack or delamination within the stacked structure, the crosssectioning approach using focused ion beam (FIB) and scanning electron microscopy (SEM) technique was used.…”

“…The application be found in the wire bonding process on the bond pad of an integrated circuit (IC) device, where the damage-sensitive pad can be identified and handled with care. 40,41 Furthermore, the methodology can be implemented in terms of design rules or guidelines for the bond pad stack structure, or even as a mechanical screening tool for wafer quality check, which will eventually enable resilient statements for improving product quality and reliability of IC chips.…”

“…Since the cracking of the brittle layer is not visible and difficult to detect, it is important to understand and predict the damage behavior and its occurrence, especially in the application of interconnection assembly process for microelectronics devices and MEMSs. 40,41 This paper presents an indentation damage test system that uses an instrumented micro-indentator together with an acoustic emission (AE) sensor for crack detection in the bare Si and various thin-films stacked specimens, i.e., metal coating over dielectric layer on the Si substrate, during indentation loading-unloading cycles. The specimens are then examined in detail by both delayering and crosssectioning failure analysis techniques.…”