• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.273-279
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• 2006

This study explored the possibility of porous Si (PS) formed by indirect electrode anodization used for effective isolation material for radio frequency integrated circuits (RFIC). We investigated the effect of current density and reaction time on the porosity size and depth, and X-ray diffraction of bulk Si and porous Si to evaluate the change in lattice parameter. Porosity size and depth usually increases with an increase in the current density and reaction time. PS increases the lattice parameter of Si compared to the bulk Si which causes the compressive stress of around 8 MPa. PS formed by the method is believed to be suitable for isolation material for RFIC because it is simple process as well as good compatibility to Si VLSI process.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.627-634
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• 2009

This study was done to find out the formation mechanism of chlorate by electrochemical process using chloride ion ($Cl^-$) as an electrolyte. Firstly, the effective factors such as pH and initial chloride concentration were figured out to see the formation property of chlorate during electrolysis. And the relation of free chlorine, and mixed oxidants such as OH radical and ozone with chlorate were estimated to concretize the formation mechanism. As a result, it was found that the major reaction of chlorate formation would be electrochemical reaction with free chlorine, and also the direct oxidation of chloride ion and the reaction by OH radical were participated in the formation of chlorate. Moreover, it was observed that formed chlorate was oxidized to perchlorate. Lastly, the optimum condition was recommended by comparing free chlorine with chlorate concentration during the electrochemical process with the different electrode separation.