Etching system and method for forming multiple porous semiconductor regions with different optical and structural properties on a single semiconductor wafer

Abstract

Disclosed is an electrochemical etching system with localized etching capability. The system allows multiple different porous semiconductor regions to be formed on a single semiconductor wafer. Localized etching is achieved through the use of one or more stationary and/or movable computer-controlled inner containers operating within an outer container. The outer container holds the electrolyte solution and acts as an electrolyte supply source for the inner container(s). The inner container(s) limit the size of the etched region of the semiconductor wafer by confining the electric field. Additionally, the current amount passing through each inner container during the electrochemical etching process can be selectively adjusted to achieve a desired result within the etched region. Localized etching of sub-regions within each etched region can also be achieved through the use of different stationary and/or moveable electrode structures and shields within each inner container. Also disclosed are associated method embodiments.