COLOR-SENSITIVE SI-PHOTODIODE USING POROUS SILICON INTERFERENCE FILTERS

A new method for the fabrication of color-sensitive Si-photodiodes is presented. Color sensitivity was achieved by using porous silicon mult ilayer stacks which act as interference filters if the formation param eters are controlled carefully. These filters were integrated in the u pper, p(+)-type part of a p(+)n-junction. As expected, the spectral re sponse of the photodiodes was determined by the transmission spectra o f the filters, while the porous silicon had no significant influence o n the electrical characteristics. The great advantage of this method o ver conventional ones is that it makes very cheap, fast filter fabrica tion requiring no expensive deposition process possible.