Electrochemical synthesis of crystalline compound or alloy films
OwnerShalini Menezesinventor
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Abstract
A new method to synthesize crystalline films, superlattices and multilayered devices based on metallic or semiconductor compounds or alloys in electrolyte media on non-crystalline substrates. An automated sequence of flow, equilibration and underpotential electrodeposition from a single electrolyte comprising the film constituents leads to the synthesis of stoichiometric, epitaxial layers. The invention process is based on a new concept of electrochemical molecular layer epitaxy; it provides a relatively simple, fast and inexpensive method to fabricate a wide range of high quality technological materials, ranging from large-area single phase films to multiple quantum-well structures.
Claims20
A method for electrochemically synthesizing epitaxial molecular layers of a semiconductor onto a substrate from an electrolyte containing ions of different elements that constitute said semiconductor, comprising the steps of:
- a) providing a means to predetermine process parameters;
- b) providing said electrolyte;
- c) providing a means for controlling the flow and equilibration of said electrolyte;
- d) providing a means for controlling the electrochemical potential of said substrate;
- e) electrodepositing the ions from said electrolyte simultaneously to form at least one molecular layer of desired stoichiometry using said predetermined parameters in one cycle;
- and
- f) repeating step (e) until a desired film thickness for said semiconductor is obtained.
A method for electrochemically synthesizing a periodic superlattice on a substrate with each period containing alternate layers of at least two materials and each material layer comprising at least one molecular layer, comprising the steps of:
- a) providing a plurality of electrolytes, each containing a predetermined ratio of different ions of elements constituting said molecular layer, in effective amounts for yielding the desired composition of said material;
- b) providing a means for switching and controlling the flow of said electrolytes into a deposition chamber;
- c) providing a means for controlling the electrochemical potential of said substrate for the deposition of said molecular layers for each material;
- d) electrodepositing the different ions from one of said each electrolyte simultaneously to form a plurality of molecular layers with desired stoichiometry to produce a first superlattice material layer of a desired layer thickness;
- e) repeating step (d) for the other superlattice layers in said period, using each of the other electrolytes;
- and
- f) repeating the sequence of depositing all the superlattice layers in said period to construct a desired device structure.
A method for electrochemically synthesizing molecular layers of a material onto a substrate from an electrolyte containing ions of different elements that constitute said material comprising the steps of:
- a) providing said electrolyte;
- b) providing a means for controlling the flow and equilibration of said electrolyte;
- c) providing a means for controlling the electrochemical potential of said substrate;
- d) electrodepositing said different elements simultaneously to form at least one molecular layer of desired stoichiometry using predetermined parameters in one cycle;
- and
- e) repeating step (d) until a desired film thickness for the material is obtained.
Dependencies are inferred from the claim text.