Electrochemical micromachining three-dimensional

A planar substrate, such as silicon wafer, could be micromachined by a sequence of deposition and etching processes. This results in three-dimensional microstructures which can be implemented in cavities, grooves, holes, diaphragms, cantilever beams etc. The process referred to as silicon micromachining often employs anisotropic etchants such as potassium hydroxide and ethylene diamine pyrocatechol. The crystallographic orientation is important as the above-mentioned etchants show an etch-rate anisotropy. The ratio for the (100)-, (110)- and (111)- planes is typically 100 16 1. The technique of electrochemical etch stop could be applied for control of the microstructural dimensions. An alternative... 

M. Sterner, N. Roxhed, G. Stemme, J. Oberhammer, Electrochemically assisted maskless selective removal of metal layers for three-dimensional micromachined SOI RE MEMS transmission lines and devices, J. Microelectromech. Syst. 20 (4) (2011) 899-907. 

Such confined etchant layer technique has been applied to achieve effective three-dimensional (3D) micromachining on n-GaAs and p-Si. It operates via an indirect electrochemical process and is a maskless, low-cost technique for microfabrication of arbitrary 3D structures in a single step [109]. It has also been presented that free-standing Si quantum wire arrays can be fabricated without the use of epitaxial deposition or lithography... 

Functional Three-dimensional Micromachined Electrochemical Devices... 

A three-dimensional modular setup for a miniaturized analysis system for flowing streams is presented The system uses silicon micromachined pumps and flow manifolds in combination with electrochemical sensors or optical detection Applications range from simple ion concentration measurements with ISFETs to a multi-step chemical analysis of phosphate Miniaturization of the flow systems leads to a substantial reduction in reagent consumption... 

---