Formation and Characterization of Porous Silicon

In this paper, the anodization of porous silicon is explained. Porous silicon is formed through electrochemical etching. Several parameters capable to be varied are explained to garner �different results. In addition to this, a relay timer and a four point probe were fabricated, to aid in the anodization process and the characterization process, respectively. Electrical characterization was done with this four point probe, which was constructed at Fort Lewis College with a cost effective setup. The fabrication process is examined in addition to the results achieved through the use of the four point probe. A relationship of resistivity and an- odization is found, as well as the uniformity of the anodization in a temporal perspective. Anodized wafers depicted higher resistivities than unanodized wafers. Furthermore, longer anodized wafers had more uniform anodizations. It was found that longer four point probe measurements read increased resistivities, a result that should not have been the case. This was likely caused by fluid within the pores, and as such allowed a potential application for these wafers to be used as a humidity sensor. With an applied electrical current, the fluid can evaporate, and increase the resistivity. This can be analyzed in such a way that the precipitation in the air can be monitored. These wafers can be recreated for use in electrical devices, physical �filters, sensors, or other applications