Full-field wafer level thin film stress measurement by phase-stepping shadow Moire/spl acute/

Current methodologies used for the inference of thin film stress through system curvature measurements are strictly restricted to stress and curvature states which are assumed to remain uniform over the entire film/substrate system. Recently Huang, Rosakis, and co-workers [Acta Mech. Sinica, 21, pp. 362–370 (2005); J. Mech. Phys. Solids, 53, 2483–2500 (2005); Thin Solid Films, 515, pp. 2220–2229 (2006); J. Appl. Mech., in press; J. Mech. Mater. Struct., in press] established methods for the film/substrate system subject to nonuniform misfit strain and temperature changes. The film stresses were found to depend nonlocally on system curvatures (i.e., depend on the full-field curvatures). These methods, however, all assume uniform substrate thickness, which is sometimes violated in the thin film/substrate system. Using the perturbation analysis, we extend the methods to nonuniform substrate thickness for the thin film/substrate system subject to nonuniform misfit strain.

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Apparatus for thin-film stress measurement with integrated four-point bending equipment: Performance and results on Cu films

Review of Scientific Instruments ◽

10.1063/1.1326925 ◽

2000 ◽

Vol 71 (12) ◽

pp. 4479 ◽

Cited By ~ 15

Author(s):

V. Weihnacht ◽

W. Brückner ◽

C. M. Schneider

Keyword(s):

Thin Film ◽

Stress Measurement ◽

Film Stress ◽

Cu Films ◽

Thin Film Stress ◽

Four Point Bending ◽

Equipment Performance

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Thin Film Stress Measurement with a Tunneling Sensor

MRS Proceedings ◽

10.1557/proc-546-45 ◽

1998 ◽

Vol 546 ◽

Author(s):

P. Zhang ◽

R. P. Vinci ◽

J. C. Bravman ◽

T. W. Kenny

Keyword(s):

Thin Film ◽

Stress Measurement ◽

Thin Film Deposition ◽

In Situ Stress ◽

Film Deposition ◽

Film Stress ◽

Stress Monitoring ◽

Thin Film Stress ◽

Basic Measurement ◽

A New Technique

AbstractA new technique of measuring thin film stress with a tunneling sensor is presented. Basic measurement concepts, preliminary results on thin film stress measurement, and fabrication processes for the tunneling stress measurement sensor are described. The feasibility of implementing this technique for in-situ stress monitoring during thin film deposition demonstrated.

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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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