Devices and methods for electrochemical liquid phase epitaxy
AssigneeThe Regents of the University of Michigan
InventorsStephen Maldonado, Joshua DeMuth, Eli Fahrenkrug
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Abstract
Electrochemical liquid phase epitaxy (ec-LPE) processes and devices are provided that can form precipitated epitaxial crystalline films or layers on a substrate. The precipitated films may comprise a semiconductor, such as germanium, silicon, or carbon. Dissolution into, saturation within, and precipitation of the semiconductor from a liquid metal electrode (e.g., Hg pool) near an interface region with a substrate yields a polycrystalline semiconductor material deposited as an epitaxial film. Reactor cells for use in an electrochemical liquid phase epitaxy (ec-LPE) device are also provided that include porous membranes to facilitate formation of the precipitated epitaxial crystalline films.
Claims20
A reactor cell for an electrochemical liquid phase epitaxy (ec-LPE) device, the reactor cell comprising:
- a substrate;
- a liquid metal electrode adjacent to the substrate, wherein an interface region is defined between the substrate and the liquid metal electrode and the liquid metal electrode is in electrical communication with a second electrode having a second opposite polarity from the liquid metal electrode;
- a porous membrane disposed on a side of the liquid metal electrode opposite from the substrate;
- and
- a liquid electrolyte source disposed adjacent to and in fluid communication with the porous membrane, the source comprising a liquid electrolyte that comprises an oxide compound of a semiconductor element;
- wherein the substrate, liquid metal electrode, and porous membrane are compressed together under pressure and the reactor cell is configured in a presence of an electric potential to form an epitaxial layer of precipitated semiconductor element on the substrate near the interface region.
An electrochemical liquid phase epitaxy (ec-LPE) device comprising:
- a reactor cell comprising:
- a substrate;
- a liquid metal electrode adjacent to the substrate, wherein an interface region is defined between the substrate and the liquid metal electrode and the liquid metal electrode is in electrical communication with a second electrode having a second opposite polarity from the liquid metal electrode;
- a porous membrane disposed on a side of the liquid metal electrode opposite from the substrate;
- and
- a liquid electrolyte source disposed adjacent to and in fluid communication with the porous membrane, the source comprising liquid electrolyte that comprises an oxide compound of a semiconductor element;
- wherein in a presence of an electric potential, the semiconductor element forms an epitaxial layer on the substrate at the interface region;
- a pair of clamping plates sandwiching the reactor cell, wherein the clamping plates compress the substrate, liquid metal electrode, and porous membrane in the reactor cell together;
- a liquid metal delivery system in fluid communication with the liquid metal electrode in the reactor cell;
- and
- a source of potential in electrical communication with the liquid metal electrode and the second electrode.
A method for electrochemical liquid phase epitaxial (ec-LPE) semiconductor growth, the method comprising:
- applying an electric potential to a reactor cell comprising:
- a substrate;
- a liquid metal electrode adjacent to the substrate;
- a porous membrane disposed on a side of the liquid metal electrode opposite from the substrate;
- and
- a liquid electrolyte source disposed adjacent to and in fluid communication with the porous membrane, the source comprising a liquid electrolyte comprising an oxide compound of a semiconductor element, wherein the applying of the electric potential drives an electrochemical reduction reaction so that the semiconductor element enters the liquid metal electrode where it precipitates out of solution on the substrate as an epitaxial film comprising the semiconductor element.
Dependencies are inferred from the claim text.