Elimination of stress-induced curvature in microcantilever infrared focal plane arrays

Huang, Shusen; Li, Biao; Zhang, Xin

doi:10.1016/j.sna.2005.09.012

Cited by 20 publications

(20 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermal annealing can modify the curvature of thin-film structures [40,41]. Also, temperature effects on curvature of released BEOL layers were already identified in [42].…”

Section: K Temperature and Time Effects On Curvaturementioning

confidence: 95%

Curvature of BEOL Cantilevers in CMOS-MEMS Processes

Valle

Fernandez

Madrenas

et al. 2017

J. Microelectromech. Syst.

View full text Add to dashboard Cite

This article presents the curvature characterization results of released back-end-of-line (BEOL) 5 µm-wide cantilevers for two different 0.18 µm 1P6M complementary metal-oxide semiconductor microelectromechanical systems (CMOS-MEMS) processes. Results from different runs and lots from each foundry are presented. The methodology and accuracy of the characterization approach, based on optical measurements of test cantilever curvature are also discussed. Special emphasis is given to the curvature average and variability as a function of the number of stacked layers. Analythical equations for modeling the bending behavior of stacked cantilevers as a function of the tungsten (W) vias that join the metal layers are presented. In addition, the effect of various post-processing conditions and design techniques on the curvature of both single and stacked cantilevers is analyzed. In particular, surpassing certain timedependent temperature stress conditions after release lead to curvature shifts larger than one order of magnitude. Also, the W via design was found to strongly affect the curvature of the test cantilevers.

show abstract

“…Thermal annealing can modify the curvature of thin-film structures [40,41]. Also, temperature effects on curvature of released BEOL layers were already identified in [42].…”

Section: K Temperature and Time Effects On Curvaturementioning

confidence: 95%

Curvature of BEOL Cantilevers in CMOS-MEMS Processes

Valle

Fernandez

Madrenas

et al. 2017

J. Microelectromech. Syst.

View full text Add to dashboard Cite

show abstract

“…The metallic layer is deposited using electron beam and thermal evaporation, and the device is then released from the substrate using xenon difluoride (XeF 2 ) gaseous etch. Because significant residual stresses were present in the film, neutral ion bombardment was used to balance the residual stresses of the film with application of an induced compressive stress layer [28][29][30] . Figures 11, 12, and 13 show scanning electron microscope photographs of the modified cantilever, trapezoid, and spiral films, respectively, fabricated for this study.…”

Section: Figure 10 Configuration Of Thin Film Layersmentioning

confidence: 99%

Energy Scavenging for Body Sensor Networks

Reilly¹,

Wright²

2007

Proceedings of the Second International Conference on Body Area Networks BodyNets

View full text Add to dashboard Cite

For small, inexpensive, ubiquitous wireless sensors to be realized, all constituents of the device, including the power source, must be directly integratable. For long term application the device must be capable of scavenging power from its surrounding environment. An apparent solution lies in conversion of mechanical energy to electrical output via the growth and direct integration of piezoelectric thin films unimorphs with the wireless electronics. Current devices are limited by both their design and material selection. This paper will address optimizing the design of microscale devices by showing how the device strains under input vibration are directly proportional to its power output, and by proposing some designs which increase the strain distribution over more of the device volume. Finite element modeling (ANSYS ®) was used to determine the strain distribution in a cantilever, modified cantilever, trapezoid, and spiral shaped piezoelectric microscale energy scavenging system. The devices have been fabricated and initial results are presented.

show abstract

“…The position of the pixel can be read out either electronically (as capacitance) or optically. There are currently several groups working on such systems, most notably Oak Ridge [8,10], Multispectral Imaging (MII) [5,6], Agiltron [9], and various university groups in the USA [14][15][16][17][18][19] and Asia [20,21]. MII has focused on electrical readout, while Oak Ridge and Agiltron have focused on optical readout.…”

Section: Introductionmentioning

confidence: 99%