Methods for fabricating and etching porous silicon carbide structures
AssigneeElwha LLC
InventorsRachel Cannara, Emma Rae Mullen, Fred Sharifi
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Abstract
The present disclosure relates to methods of fabricating a porous structure, such as a porous silicon carbide structure. The methods can include a step of providing a structure to be rendered porous, and a step of providing an etching solution. The methods can also include a step of electrochemically etching the structure to produce pores through at least a region of the structure, resulting in the formation of a porous structure. The morphology of the porous structure can be controlled by one or more parameters of the electrochemical etching process, such as the strength of the etching solution and/or the applied voltage.
Claims34
A method of fabricating a porous silicon carbide structure having a selected morphology, comprising:
- providing a silicon carbide structure;
- providing an etching solution comprising a reducing agent and an oxidizing agent;
- electrochemically etching the silicon carbide structure with the etching solution to produce pores through a region of the silicon carbide structure to form a porous silicon carbide structure, wherein electrochemically etching the silicon carbide structure comprises applying a voltage to a surface of the silicon carbide structure to produce a current through the region of the silicon carbide structure;
- monitoring a slope of the current versus time;
- and
- controlling an etch propagation rate of the etching solution through the region of the silicon carbide structure to avoid a change in the monitored slope and achieve the selected morphology, wherein the current is proportional to a removal rate of material, and wherein the slope is negative.
A method of fabricating a porous structure, comprising:
- providing a starting structure to be rendered porous, wherein the starting structure comprises silicon carbide;
- providing an etching solution comprising a selected reducing agent and an oxidizing agent;
- electrochemically etching the starting structure with the etching solution to produce pores through a region of the starting structure to form a porous structure, wherein electrochemically etching the structure comprises applying a voltage to a surface of the structure to produce a current through the region of the structure;
- monitoring a slope of the current versus time;
- and
- controlling an etch propagation rate of the etching solution through the region of the structure to avoid a change in the monitored slope and achieve a selected porosity, wherein the current is proportional to a removal rate of material, and wherein the slope is negative.
A method of fabricating a porous semiconductor structure via an electrochemical etch process, comprising:
- providing a semiconductor structure comprising silicon carbide;
- providing an etching solution comprising a reducing agent and an oxidizing agent;
- selecting a concentration of the reducing agent;
- electrochemically etching the semiconductor structure with the etching solution to produce pores through a region of the semiconductor structure to form a porous semiconductor structure, wherein electrochemically etching the semiconductor structure comprises selecting a voltage and applying the selected voltage to a surface of the semiconductor structure to produce a current through the region of the semiconductor structure;
- monitoring a slope of the current versus time;
- and
- controlling an etch propagation rate of the etching solution through the region of the semiconductor structure to avoid a change in the monitored slope and achieve a selected morphology, wherein the current is proportional to a removal rate of material, and wherein the slope is negative,
- wherein the porous semiconductor structure comprises a selected porosity.
Dependencies are inferred from the claim text.