Photoelectrochemical etching of semiconductors
AssigneeBell Telephone Laboratories, Incorporated
InventorsPaul A. Kohl, Frederick W. Ostermayer, Jr.
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Abstract
A process is described for etching p-type semiconductors using a photoelectrochemical etching process. This etching process is highly advantageous because the etching site is highly defined by the incident light and the etching rate can be controlled in a number of ways including light intensity and electrode potential.
Claims32
A process for fabricating devices comprising at least one compound semiconductor material selected from the group consisting of III-V and II-VI compound semiconductor material with a given band gap in which the compound semiconductor material is photoelectrochemically etched by a procedure comprising the step of passing electrical energy through a semiconductor electrode comprising compound semiconductor material, electrochemical solution and counter electrode characterized in that;
- (a) the compound semiconductor material is p-type
- (b) the electrical energy is applied to the semiconductor electrode in the form of pulses comprising reducing pulses and oxidizing pulses, in which said reducing pulses have a semiconductor electrode potential such as to reduce the semiconductor material and said oxidizing pulses have a semiconductor electrode potential such as to oxidize the semiconductor material;
- (c) the electrochemical solution removes the reduction and oxidation products of the photoelectrochemical etching reaction;
- and
- (d) the semiconductor material is irradiated by radiation with photon energy greater than the band gap of the semiconductor material.
Dependencies are inferred from the claim text.