US 2010/0187126 A1 · 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.

Claims25

Dependent claims

An electrochemical etching system for etching a workpiece, said electrochemical etching system comprising:

a first container having a first end and a second end, said first end having an opening;
a first electrode within said first container at said second end;
a second electrode;
an electrolyte solution;
a second container larger than said first container, said second container containing said electrolyte solution and further containing within said electrolyte solution said workpiece, said second electrode adjacent to a bottom surface of said workpiece and said first container with said opening adjacent to a top surface of said workpiece opposite said second electrode;
and
a current source connected to said first electrode and said second electrode, said current source providing a current flow through said electrolyte solution between said first electrode and said second electrode, said current flow causing a selective etch of only a region of said top surface of said workpiece adjacent to said opening.

4 more elements

An electrochemical etching system for etching a workpiece, said electrochemical etching system comprising:

a plurality of first containers, each first container having a first end and a second end, said first end having an opening;
a plurality of first electrodes, each first electrode being positioned within a first container at said second end;
a plurality of second electrodes;
an electrolyte solution;
a second container larger than said first containers, said second container containing said electrolyte solution and further containing within said electrolyte solution said workpiece, said second electrodes adjacent to a bottom surface of said workpiece and said first containers, said opening of each one of said first containers being adjacent to a top surface of said workpiece opposite one of said second electrodes, thereby forming multiple first electrode-second electrode pairs;
and
a plurality of individually controllable current sources, each current source being connected to a corresponding first electrode-second electrode pair and further being capable of providing a current flow through said electrolyte solution between said corresponding first electrode-second electrode pair in order to selectively etch a specific region of said top surface of said workpiece.

4 more elements

A method for electrochemical etching of a workpiece, said method comprising:

providing an electrochemical etching system, said system comprising:
a plurality of first containers, each first container having a first end and a second end, said first end having an opening;
a plurality of first electrodes, each first electrode being positioned within a first container at said second end;
a plurality of second electrodes;
an electrolyte solution;
a second container larger than said first containers, said second container containing said electrolyte solution, said first containers and said second electrodes;
placing said workpiece in said electrolyte solution such that said second electrodes are adjacent to a bottom surface of said workpiece and further such that said opening of each one of said first containers is adjacent to a top surface of said workpiece opposite one of said second electrodes, thereby forming multiple first electrode-second electrode pairs;
and
individually controlling current flow through said electrolyte solution between each one of said multiple first electrode-second electrode pairs so as to selectively etch multiple regions of said top surface of said workpiece.

6 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims25