Semiconductor etching paste and the use thereof for localized etching of semiconductor substrates
AssigneeInteruniversitair Microelektronica Centrum vzw
InventorsJozef Szlufcik, Emmanuel Van Kerschaver, Christophe Allebé
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Abstract
A method of etching a semiconductor substrate is described, the method comprising the steps of applying a paste containing an etchant to the substrate, and carrying out a thermal processing step to etch a part or a layer of the substrate where the paste has been applied. The etchant paste is preferably a caustic etching paste. The etchant paste may be applied selectively to a major surface of the substrate to form a pattern of applied paste. For example, the paste may be applied by a printing method, such as screen-printing. The method may be used to produce solar cells.
Claims32
A method of etching a semiconductor substrate, the method comprising the steps of:
- doping a region of a substrate to yield a doped region of the substrate;
- applying a caustic etching paste comprising an etchant and a thickener to the doped region of the substrate, wherein the semiconductor substrate is selected from the group consisting of a microcrystalline silicon substrate, a polycrystalline silicon substrate, an amorphous silicon substrate, a doped silicon substrate, a gallium arsenide substrate, a gallium arsenide phosphide substrate, a germanium substrate, and a silicon germanium substrate, and wherein the etchant is a water-based etchant selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, combinations thereof, and derivatives thereof;
- and
- heating the substrate, such that the part or the layer of the substrate upon which the etching paste has been applied is etched.
A method of etching a semiconductor substrate, the method comprising the steps of:
- forming at least one metal contact on a base region of the substrate;
- forming at least one metal contact on an emitter region of the substrate;
- applying a caustic etching paste comprising an etchant and a thickener to a part or a layer of the substrate, wherein the semiconductor substrate is selected from the group consisting of a microcrystalline silicon substrate, a polycrystalline silicon substrate, an amorphous silicon substrate, a doped silicon substrate, a gallium arsenide substrate, a gallium arsenide phosphide substrate, a germanium substrate, and a silicon germanium substrate, and wherein the etchant is a water-based etchant selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, combinations thereof, and derivatives thereof;
- and
- heating the substrate, such that the part or the layer of the substrate upon which the etching paste has been applied is etched.
Dependencies are inferred from the claim text.