Microsystems elements based on free-standing thick-films made with a new sacrificial layer process

2008 ◽  
Vol 48 (6) ◽  
pp. 872-875 ◽  
Author(s):  
Claude Lucat ◽  
Patrick Ginet ◽  
Christophe Castille ◽  
Hélène Debéda ◽  
Francis Ménil
Keyword(s):  
Sacrificial Layer ◽  
Thick Films ◽  
Free Standing

Feasibility of screen-printed PZT microceramics for Structural Health Monitoring piezocomposites applications

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000020-000025
Author(s):  
Hélène DEBEDA ◽  
Riadh LAKHMI ◽  
Isabelle FAVRE ◽  
Jonathan ARGILLOS ◽  
Mario MAGLIONE ◽  
...  
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Thick Films ◽  
Impedance Analysis ◽  
High Porosity ◽  
Structural Health ◽  
Monitoring Applications ◽  
Screen Printing Technology

Using the association of the low-cost screen-printing technology with the sacrificial layer method, the feasibility of totally released piezoelectric thick-films microceramics of gold electroded PZT type is studied. After the deposition of the sacrificial layer on an alumina substrate and subsequent printing and drying of gold, PZT and gold layers, the final firing is performed at low temperature. This is followed by the releasing step of the Au/PZT/Au in diluted acidic solution. Impedance analysis shows that the electrical properties and electromechanical coefficients of poled PZT thick-films are still lower than those of PZT ceramics. This result is correlated to the high porosity rate of the PZT layer. However these piezoelectric microceramics present a good electromechanical behaviour and can be used as sensors when solicited by vibrations or as actuators to generate vibrations in a structure on which they are bonded. Moreover, the successful fabrication associated to a good electromechanical signature on a metallic test structure suggests Structural Health Monitoring applications.

scholarly journals The Role of Sacrificial and/or Protective Layers to Improve the Sintering of Electroactive Ceramics: Application to Piezoelectric PZT-Printed Thick Films for MEMS

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 453-475
Author(s):  
Hélène Debéda ◽  
Maria-Isabel Rua-Taborda ◽  
Onuma Santawitee ◽  
Simon Grall ◽  
Mario Maglione ◽  
...  
Keyword(s):  
Thick Film ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Thick Films ◽  
Protective Layer ◽  
Protective Layers ◽  
Plasma Sintering ◽  
Wide Range ◽  
Spark Plasma ◽  
Pros And Cons

Piezoelectric thick films are of real interest for devices such as ceramic Micro-ElectroMechanical Systems (MEMS) because they bridge the gap between thin films and bulk ceramics. The basic design of MEMS includes electrodes, a functional material, and a substrate, and efforts are currently focused on simplified processes. In this respect, screen-printing combined with a sacrificial layer approach is attractive due to its low cost and the wide range of targeted materials. Both the role and the nature of the sacrificial layer, usually a carbon or mineral type, depend on the process and the final device. First, a sacrificial layer method dedicated to screen-printed thick-film ceramic and LTCC MEMS is presented. Second, the recent processing of piezoelectric thick-film ceramic MEMS using spark plasma sintering combined with a protective layer approach is introduced. Whatever the approach, the focus is on the interdependent effects of the microstructure, chemistry, and strain/stress, which need to be controlled to ensure reliable and performant properties of the multilayer electroceramics. Here the goal is to highlight the benefits and the large perspectives of using sacrificial/protective layers, with an emphasis on the pros and cons of such a strategy when targeting a complex piezoelectric MEMS design.

Porous Silicon as a Sacrificial Material for Microstructures Fabrication

1999 ◽  
Vol 605 ◽  
Author(s):  
M. Morel ◽  
M. Le Berre ◽  
V. Lysenko ◽  
G. Delhomme ◽  
A. Dittmar ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Sacrificial Layer ◽  
Formation Rate ◽  
Free Standing ◽  
Wide Range ◽  
Silicon Bulk ◽  
Reduced Costs ◽  
Optimized Conditions ◽  
Koh Etching

AbstractPorous silicon (PS) is generated by electrochemical etching in hydrofluoric acid (HF). Recently porous silicon has been applied to micromachining and micro-devices as an alternate material, this material being used as a sacrificial layer. This technology competes with conventional techniques like surface and bulk micromachining regarding its speed, simplicity and reduced costs. A wide range of microstructures and free-standing structures can be fabricated with a large freedom of design in relation to the isotropic behavior of the etching. A sacrificial layer may be realized fast over varying thickness (PS formation rate 45 μm/h compared to silicon bulk micromachining rate 20 μm/h for KOH etching).This contribution is devoted to the materials aspects of patterning and processing: we will show how basic microstructures (trenches, polysilicon cantilevers, polysilicon free-standing membranes) may be fabricated using a very simple process based on a single photolithography. The important points are the choice of the mask, porous silicon properties as a function of its formation parameters and the choice of the solution removing the sacrificial layer. The morphology and porosity of the porous silicon layers are indeed mainly determined by the electrolyte composition and by the current density for a given substrate type. Optimized conditions (HF 15% and 80 mA/cm2) lead us to an appropriate porous silicon. Finally the applicability of this technology for various microsensors will be underlined.

Curvature Evaluation of Si/3C-SiC/Si Hetero-Structure Grown by Chemical Vapor Deposition

2014 ◽  
Vol 778-780 ◽  
pp. 255-258
Author(s):  
Ruggero Anzalone ◽  
Massimo Camarda ◽  
Andrea Severino ◽  
Nicolo’ Piluso ◽  
Francesco La Via
Keyword(s):  
Sacrificial Layer ◽  
Chemical Vapor ◽  
Drift Region ◽  
Free Standing ◽  
Hetero Structure ◽  
Wafer Curvature ◽  
Transmission Electron ◽  
Standing Structure ◽  
Optical Profilometer ◽  
Si Films

In this work we analyzed the variation of wafer curvature due to the growth of thin Si layers on top of 3C-SiC/Si films. The final Si/3C-SiC/Si hetero-structure, allows not only to have a deeper understanding of the stress within the different layers, but can also be used for MEMS applications, using the Si film as sacrificial layer in order to obtain 3C-SiC free-standing structure, or for electronic application, e.g. using the thin Si layer as high quality MOSFET channel and the SiC layer as the drift region. In details, the influence on wafer curvature by the growth of thin Si layer on top on the 3C-SiC/Si film as been studied by optical profilometer. A theoretical model was also applied in order to fit the measured curvature of the hetero-structure and optimize the system. Finally, in order to study the morphology of the hetero-structure micro-Raman spectroscopy and Transmission Electron Microscopy (TEM) measurements has been performed.

The free-standing multilayer thick films of 0.7Pb(Zr0.46Ti0.54)O3–0.1Pb(Zn1/3Nb2/3)O3–0.2Pb(Ni1/3Nb2/3)O3 with low co-fired temperature

2018 ◽  
Vol 29 (14) ◽  
pp. 11664-11671 ◽  
Author(s):  
Jifeng Gao ◽  
Weibing Ma ◽  
Yixuan Yang ◽  
Jingdong Guo ◽  
Huaidang Zhao ◽  
...  
Keyword(s):  
Thick Films ◽  
Free Standing

Near-Infrared Light-Stimulus-Responsive Film as a Sacrificial Layer for the Preparation of Free-Standing Films

Langmuir ◽  
2016 ◽  
Vol 32 (14) ◽  
pp. 3393-3399 ◽  
Author(s):  
Chunyang Bao ◽  
Benhua Ma ◽  
Jiale Liu ◽  
Zhennan Wu ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Light Stimulus ◽  
Sacrificial Layer ◽  
Infrared Light ◽  
Free Standing ◽  
Near Infrared Light ◽  
Stimulus Responsive

Single-domain Yba2Cu3Oy thick films and fabrics prepared by an infiltration and growth process

2001 ◽  
Vol 16 (4) ◽  
pp. 955-966 ◽  
Author(s):  
E. Sudhakar Reddy ◽  
J. G. Noudem ◽  
M. Tarka ◽  
G. J. Schmitz
Keyword(s):  
Liquid Phase ◽  
Thick Film ◽  
Growth Process ◽  
Thick Films ◽  
Solidification Process ◽  
Film Coating ◽  
Single Domain ◽  
Free Standing ◽  
Liquid Phases ◽  
Woven Structure

An infiltration and growth process has been developed to produce single-domain Yba2Cu3Oy(123) as thick films on various substrates or as self-supporting fabrics. Commercially available Y2O3 cloths of square woven or satin woven structure were infiltrated with liquid phases from a suitable source containing barium cuprates and copper oxides and subsequently converted into Y2BaCuO5(211) and −123 phases by a series of distinct peritectic reactions. Depending on the final form of 123, the Y2O3 cloth was either clamped firmly at corners to produce a self-supporting 123 fabric or placed on a suitable substrate to result in a thick film coating of 123. The source material for the liquid phase being in the form of solid blocks was placed at corners of the cloth in the case of free-standing 123 fabrics. In case of the thick film configuration the liquid phase powder was spread on the surface of the Y2O3 cloth. A small c-axis-oriented MgO or Nd(123) seed was used to generate an oriented 123 domain in the infiltrated fabric. The solidification process was optimized to transform the entire Y2O3 fabric into a single-domain 123. The microstructure of the single domain was optimized in terms of 211 size and content for high Jc. A detailed description of the process, the growth mechanism, the resulting microstructures was given, and basic superconducting properties of the new form of 123 are briefly discussed.

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