Embedded thin films

A method of forming a ceramic film on a substrate having a conductive surface, comprising:

• providing at least one conductive surface portion on a substrate, subject to corrosion by at least one component of a solution containing at least one ceramic film precursor;
• immersing the substrate having the conductive surface portion in the solution;
• forming the ceramic film on the substrate from the at least one ceramic film precursor, by applying a voltage potential to the conductive surface with respect to a counter electrode in the solution and converting at least one ceramic film precursor through an electrochemical reaction involving an oxidation of the at least one ceramic film precursor, for a sufficient time to promote formation of the film to a desired thickness, wherein the at least one film precursor is consumed and at least on byproduct generated in the solution;
• and
• thermodynamically limiting corrosion of the conductive surface resulting from at least one reaction with the solution proximate to the conductive surface, by at least concurrently controlling:
• the applied voltage potential within a protective range that cathodically protects the conductive surface from corrosion by the at least one component and limits hydrolysis of the solution to reduce peeling of the ceramic film from the conductive surface, and
• a composition of the solution proximate to the conductive surface over time to at least partially compensate for a change in composition of the solution;
• wherein the conductive surface comprises metallic copper;
• wherein the ceramic film comprises titanium dioxide;
• wherein the solution comprises hydrogen peroxide;
• wherein the at least one ceramic film precursor comprises titanium tetrachloride;
• and
• wherein the voltage potential is between −5V and −10V.

A method for forming an electrically functional ceramic film on a conductive substrate having a surface subject to corrosion by soluble metal salts, comprising:

• immersing a substrate having a conductive portion in a solution comprising a soluble electrically functional ceramic film precursor comprising at least one soluble metal salt and a peroxide;
• applying a cathodic voltage potential to the conductive portion with respect to a counter electrode in the solution and controlling a composition of the solution, sufficient to thermodynamically protect the conductive portion from corrosion by the at least one soluble metal salt, and drive formation of an electrically functional ceramic film on the conductive substrate through at least one oxidation reaction, while limiting a hydrogen gas evolution reaction proximate to the conductive portion to reduce peeling of the electrically functional ceramic film from the conductive portion;
• and
• maintaining the applied cathodic voltage potential and controlling the composition of the solution proximate to the conductive surface for a sufficient duration to produce an electrically functional ceramic film adherent on the conductive portion substantially without corrosion of the conductive portion;
• wherein the conductive portion comprises metallic copper;
• wherein the ceramic film comprises titanium dioxide;
• wherein the peroxide comprises hydrogen peroxide;
• wherein the at least one soluble metal salt comprises titanium tetrachloride;
• and
• wherein the cathodic voltage potential is between −5V and −10V.

A method for forming functional film of a resistor or semiconductor on a portion of a substrate having a surface subject to corrosion by soluble metal salt ceramic precursors, comprising:

• providing a substrate having a substrate portion;
• depositing a resistive or semiconductive material ceramic film from a solution comprising a metal ion source and a peroxide on the substrate portion, by applying a cathodic voltage potential to the substrate portion with respect to a counter electrode in the solution, sufficient to protect the substrate portion from corrosion by the solution, and to drive formation of the resistive or semiconductive material ceramic film on the substrate portion through at least one oxidation reaction, while concurrently controlling a pH and limiting an extent of hydrolytic generation of hydrogen proximate to the substrate portion sufficient to reduce peeling of the resistive or semiconductive material ceramic film from the substrate portion after formation;
• and
• forming a conductive portion on an exposed surface of the resistive or semiconductive material film;
• wherein the substrate comprises metallic copper;
• wherein the ceramic film comprises titanium dioxide;
• wherein the peroxide comprises hydrogen peroxide;
• wherein the metal ion source comprises titanium tetrachloride;
• and
• wherein the cathodic voltage potential is between −5V and −10V.

A method of converting a titania film to a barium titanate film, comprising:

• immersing a substrate having a titania film formed on conductive portion in a solution comprising a barium salt;
• and
• applying a voltage potential to the conductive portion with respect to a counter electrode in the solution and a maintaning pH of the solution within a protective range which protects the conductive portion from corrosion by the solution which would otherwise occur under conditions of a voltage potential or a pH outside of the protective range, while limiting a production of hydrogen by hydrolysis proximate to the conductive portion to an extent sufficient to reduce peeling of the titania film from the conductive portion, to thereby permit conversion of the titania film to a barium titanate film;
• and
• wherein the voltage potential is about −0.5V;
• and
• wherein the pH is about 12.