In Situ Stress Measurement of Ni Electrodeposition Using Lateral Shearing Interferometry

Abstract

In-situ stress measurement has a significant benefit in revealing the deformation and failure mechanism during the deposition process. However, it is difficult to detect an ultrathin deposit and measure deposits of different scales simultaneously. Here, lateral shearing interferometry was used for in situ stress measurement of Ni deposits. we demonstrated that this method showed great stability and sensitivity during in situ process. Additionally, the accuracy of measurement was also been improved in terms of the measurement error (2.96%) and fluctuation (0.00035) of curvature radius. The system was capable of the measuring radius of curvature as large as 250 m. Theoretical calculation and experimental results coherently suggested that the thickness of measurable deposits can be diminished by decreasing the elastic modulus and thickness of the substrate. PMMA substrates can be used to measure the stress evolution of deposits with a thickness of more than 10 nm. Moreover, suitable substrate material and thickness for stress measurement of deposits with different scales can be selected by theoretical calculation before the experiment. This novel method provides valuable insights into the in situ stress towards the ultrathin deposit and paves the way to further understanding on the mechanism of deformation and failure of the deposition process in different states.

Optimization of Substrate Sizes for In Situ Stress Measurement in Electrodeposits Relying on Nonlinear Effects

“…The reflection was generated in the interface between the deposit and the substrate, and the reflected light was detected by the wavefront sensor. The curvature of the substrate was measured in situ by the principle of transverse shearing interference [7]. The internal stress of the deposit can be calculated from the curvature of the substrate.…”

“…In this regard, many efforts have been made to promote the accuracy of curvature measurements, including enhanced detection capabilities and improved measurement sensitivity. For example, diversified sensors are employed to enhance the detection capabilities, such as a multibeam optical stress sensor [4], Shack-Hartmann sensor [5,6], and quadri-wave lateral shearing interferometry sensor [7]; to improve the measurement sensitivity of the substrate deformation, it is shown that using low elastic modulus substrate materials (quartz glass and polymethyl methacrylate) or reducing the substrate thickness is effective, the available thickness of deposit can be reduced to about 0.1 mm [7,8]. However, beyond these attempts, an intrinsic problem is Coatings 2023, 13, 2031 2 of 16 that nonlinear effects (i.e., nonuniform curvature in different directions) are induced by large deformation of the substrate, leading to large errors in stress measurements [9,10].…”

Simultaneous two-step phase-shifting lateral shearing interferometry for aspherical surface based on an orthogonal shear displacer

“…Currently, wavefront measurement plays an increasingly important role in the optical measurement field, such as beam evaluation of laser, distortion measurement of the optical surface, aberration measurement of lenses, phases imaging of optical, etc [1][2][3][4][5][6]. However, along with the rapid development of computer processing technology, the accuracy and stability of the wavefront measurement methods are proposed higher requirements.…”

“…However, along with the rapid development of computer processing technology, the accuracy and stability of the wavefront measurement methods are proposed higher requirements. Lateral shearing interferometry (LSI) technology has become an effective tool in wavefront measurement due to its unique advantage that it does not require an ideal reference wavefront [2][3][4][5][6][7][8]. In recent years, researchers have presented many types of LSI wavefront measurement methods and have also applied different technologies to LSI design [1,3,4,6,[8][9][10].…”