Electric Field Effects on the Formation of Isolated Macro Porous Silicon

In this paper, we discuss some of the challenges involved in the formation of isolated vertical pores, thereby describing the electric field effects on the pore formation. The diameters of the pore features under investigation range from 5μm to 20μm. A variety of experiments have been conducted, which include exploration of features with large pyramidal pits, large patterned features with an array of pyramidal pits, and patterned features using a metal mask or a dielectrically isolated etch mask. Macroporous silicon is explored under these parameters for p-type (100) and p-type (111) silicon substrates using electrochemical anodization. Electric field effects on the pore profile and formation will be discussed using the experimental anodization results and electric field and process modeling analysis related to the formation of isolated pores.