A Relaxation Corrected Voltage Ramp Stress Measurement for Fast Wafer Level Reliability

Even as unit processes for high aspect ratio (HAR) through silicon via (TSV) mid-wafer front-side processing are becoming relatively mature, scaling of the TSVs and reduction of cost of ownership (COO) drive significant innovations in processes, equipment and materials. To assess their high volume manufacturing (HVM) worthiness, any new unit processes need to be evaluated with respect to yield, reliability and COO. Fully integrated product runs tend to be too slow and expensive for this purpose. At SEMATECH, we use TSV mid-wafer short loop test vehicles for rapid learning cycles through in-line electrical test (ILT) and wafer-level reliability assessments using voltage ramp dielectric breakdown (VRDB). These test vehicles contain 5 × 50 μm or 2 × 40 μm TSV comb test structures, which are testable after the first front-side metal line layer level. Novel unit processes by our associate member companies are inserted into the process flow, and are optimized and assessed using split lot experiments. Processes including TSV etch, post TSV etch cleans, dielectric liner deposition, Cu diffusion barrier and seed deposition, as well as TSV fill by Cu electrochemical deposition (ECD) were evaluated. ILT and VRDB results for short loop lots are presented and discussed.

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Transferring stress and temperature sensors for stress measurement of wafer level packaging

Microsystem Technologies ◽

10.1007/s00542-016-2902-7 ◽

2016 ◽

Vol 23 (4) ◽

pp. 975-981

Author(s):

Chuanguo Dou ◽

Heng Yang ◽

Yanhong Wu ◽

Xinxin Li

Keyword(s):

Stress Measurement ◽

Temperature Sensors ◽

Wafer Level ◽

Wafer Level Packaging

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OS3-2-6 Full-field wafer level thin film stress measurement by fringe reflection method with LCD

The Abstracts of ATEM International Conference on Advanced Technology in Experimental Mechanics Asian Conference on Experimental Mechanics ◽

10.1299/jsmeatem.2007.6._os3-2-6-1 ◽

2007 ◽

Vol 2007.6 (0) ◽

pp. _OS3-2-6-1-_OS3-2-6-5

Author(s):

T. Y. Chen ◽

S. L. Yang ◽

I. T. Hwang

Keyword(s):

Thin Film ◽

Stress Measurement ◽

Film Stress ◽

Reflection Method ◽

Wafer Level ◽

Full Field ◽

Thin Film Stress

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A Comparison of X-Ray Microdiffraction and Coherent Gradient Sensing in Measuring Discontinuous Curvatures in Thin Film: Substrate Systems

Journal of Applied Mechanics ◽

10.1115/1.2150500 ◽

2005 ◽

Vol 73 (5) ◽

pp. 723-729 ◽

Cited By ~ 16

Author(s):

Michal A. Brown ◽

Tae-Soon Park ◽

Ares Rosakis ◽

Ersan Ustundag ◽

Young Huang ◽

...

Keyword(s):

Thin Film ◽

Stress Measurement ◽

Plate Theory ◽

Measurement Tool ◽

Wafer Level ◽

Full Field ◽

X Ray ◽

Deformation State ◽

Film Substrate ◽

Si Wafer

The coherent gradient sensor (CGS) is a shearing interferometer which has been proposed for the rapid, full-field measurement of deformation states (slopes and curvatures) in thin film-wafer substrate systems, and for the subsequent inference of stresses in the thin films. This approach needs to be verified using a more well-established but time-consuming grain orientation and stress measurement tool, X-ray microdiffraction (XRD). Both CGS and XRD are used to measure the deformation state of the same W film/Si wafer at room temperature. CGS provides a global, wafer-level measurement of slopes while XRD provides a local micromeasurement of lattice rotations. An extreme case of a circular Si wafer with a circular W film island in its center is used because of the presence of discontinuous system curvatures across the wafer. The results are also compared with a theoretical model based on elastic plate analysis of the axisymmetric biomaterial film-substrate system. Slope and curvature measurements by XRD and by CGS compare very well with each other and with theory. The favorable comparison demonstrates that wafer-level CGS metrology provides a quick and accurate alternative to other measurements. It also demonstrates the accuracy of plate theory in modeling thin film-substrate systems, even in the presence of curvature discontinuities

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