Production method for composite oxide thin film and device therefor and composite oxide film produced thereby

A method of making a thin film of a composite oxide wherein the composite oxide has a basic unit cell, characterized in that the method comprises the steps of:

• heating, in a vacuum atmosphere, an oriented crystalline substrate to a selected temperature;
• forming, in said vacuum atmosphere, a buffer layer on said heated substrate by sputtering from a target for the composite oxide thin film having atoms of a selected element mixed therein in a selected amount or from a target made of a material enough matching in lattice property with said basic unit cell;
• introducing an oxidizing gas under a selected pressure into said vacuum atmosphere;
• and then
• a) forming a first block constituting said first block of said basic unit cell on said buffer layer by sputtering from a target having an atomic composition constituting said first block of said composite oxide thin film until said first block being formed has its thickness determined for said first block in said basic unit cell;
• b) forming a second block constituting said second block of said basic unit cell on said first block by sputtering from a target having an atomic composition constituting said second block of said composite oxide thin film until said second block being formed has its thickness determined for said second block in said basic unit cell;
• c) repeating a step like step a) or b) by a number determined by a type of said basic unit cell of said composite oxide thin film;
• and
• repeating steps a) to c) or c) to a) to make a thin film of composite oxide having a desired thickness.

A method of making a thin film of a Cu group high temperature superconductor wherein the superconductor has a basic unit cell comprised of a charge supply block and a superconducting block, characterized in that the method comprises the steps of:

• heating, in a vacuum atmosphere, an oriented crystalline substrate to a selected temperature;
• forming, in said vacuum atmosphere, a buffer layer on said heated substrate by sputtering from a target for the charge supply block and having atoms of a selected element mixed therein in a selected amount or from a target made of a material enough matching in lattice property with said basic unit cell;
• introducing an oxidizing gas under a selected pressure into said vacuum atmosphere;
• and then
• a) forming a first block constituting said superconducting block on said buffer layer by sputtering from a target for superconducting block until said first block being formed has its thickness determined for said superconducting block in said basic unit cell;
• b) forming a second block constituting said charge supply block on said first block by sputtering from the target for the charge supply block until said second block being formed has its thickness determined for said charge supply block in said basic unit cell;
• and
• repeating steps a) and b) or steps b) and a) to make a thin film of the Cu high temperature superconductor having a selected thickness.

A method of making a thin film of a Cu group high temperature superconductor wherein the superconductor has a basic unit cell comprised of a charge supply block and a superconducting block, characterized in that the method comprises the steps of:

• heating, in a vacuum atmosphere, an oriented crystalline substrate to a selected temperature;
• forming, in said vacuum atmosphere, a buffer block on said heated substrate by sputtering from a target for the charge supply block and having atoms of a selected element mixed therein in a selected amount or from a target made of a material enough matching in lattice property with said basic unit cell;
• introducing an oxidizing gas under a selected pressure into said vacuum atmosphere;
• and then
• a) forming a first block constituting said superconducting block on said buffer block by sputtering from a target for superconducting block until said first block being formed has its thickness determined for said superconducting block in said basic unit cell;
• b) forming a second block constituting said charge supply block on said first block by sputtering from the target for charge supply block until said second block being formed has its thickness determined for said charge supply block in said basic unit cell;
• repeating steps a) and b) to make a thin film of the Cu high temperature superconductor having a selected thickness;
• and then
• c) forming an insulating layer having a selected film thickness on said formed thin film of Cu high temperature superconductor by sputtering from a third target made of an insulating material;
• and then
• repeating steps a) and b) or steps b) and a) to make a thin film of the Cu high temperature superconductor having a selected thickness.

A method of making a composite oxide thin film, characterized in that it comprises the steps of:

• preparing a plurality of sputtering targets made of materials, respectively, having atomic compositions of a like plurality of block which constitute a basic unit cell of the composite oxide thin film;
• and
• forming on a substrate respective block of said compositions successively by sputtering from said sputtering targets by turns in successive sputtering operations each controllably so that each of said block has a film thickness determined for the corresponding block in said basic unit cell, wherein a programmed control computer is entered with input data for respective sputtering power magnitudes for said sputtering targets, rate(s) of rotation and temperature(s) of said substrate, gas flow rate(s) and pressure(s), degree(s) of vacuum, respective rates of deposition of said block on said substrate from said target materials and respective time periods for deposition of said block on said substrate determined from the respective thicknesses of said block in said basic unit cell, and respective numbers of repetition of said sputtering operations needed corresponding to a desired thickness of said composite oxide thin film;
• and thence said programmed control computer in response to these input data acts to communicate with terminal computers associated with a plurality of sputtering power supply units, a substrate holding, rotating and heating unit, shutters and their respective rotation control units, a gas flow rate and pressure control unit, and a plurality of evacuating units, respectively, to control respective operations of these units.

A method of making a Cu group high temperature superconducting thin film having a basic unit cell comprised of a charge supply block and a superconducting block, characterized in that it comprises the steps of

• preparing a first sputtering target made of a first material for the charge supply block and a second sputtering target made of a material for the superconducting block;
• and
• forming on a substrate alternately a first and a second block constituting said charge supply and superconducting block, respectively, by sputtering from said first and second targets in alternate sputtering operations each controllably so that each of said first and second block has a film thickness determined for the corresponding one of said charge supply and superconducting block in said basic unit cell, wherein a programmed control computer is entered with input date for respective sputtering power magnitudes for said first and second sputtering targets, rate(s) of rotation and temperature(a) of said substrate, gas flow rate(s) and pressure(s), degree(s) of vacuum, respective rates of deposition of said first and second block on said substrate from said first and second target materials and respective time periods for deposition of said first and second block on said substrate determined from the respective thicknesses of said charge supply and superconducting block in said basic unit cell, and respective numbers of repletion of said alternate sputtering operations needed corresponding to a desired thickness of said Cu group high temperature superconducting thin film;
• and thence said programmed control computer in response to these input data acts to communicate with terminal computers associated with a plurality of sputtering power supply units, a substrate holding, rotating and heating unit, shutters and their respective rotation control units, a gas flow rate and pressure control unit, and two evacuating units, respectively, to control respective operations of these units.

A record medium stored with a process control program for a computer to execute the controlled manufacture of a composite oxide thin film wherein there are prepared a plurality of sputtering targets made of materials having atomic compositions of a like plurality of block, respectively, which constitute a basic unit cell of the composite oxide thin film, to form on a substrate respective block of said compositions successively by sputtering from said sputtering targets by turns in successive sputtering operations each controllably so that each of said block has a film thickness determined for the corresponding block in said basic unit cell, characterized in that said process control program comprises input data for respective sputtering power magnitudes for said sputtering targets, rate(s) of rotation and temperature(s) of said substrate, gas flow rate(s) and pressure(s), degree(s) of vacuum, respective rates of deposition of said block on said substrate from said target materials and respective time periods for deposition of said block on said substrate determined from the respective thicknesses of said block in said basic unit cell, and respective numbers of repetition of said sputtering operations needed corresponding to a desired thickness of said composite oxide thin film, and said input data are enterable into a computer to have the computer communicate with terminal computers associated, respectively, with a plurality of sputtering power supply units, a substrate holding, rotating and heating unit, shutters and their respective rotation control units, a gas flow rate and pressure control unit, and a plurality of evacuating units to control respective operations of these units.

A record medium stored with a process control program for a computer to execute the controlled manufacture of a Cu group high temperature superconducting thin film having a basic unit cell comprised of a charge supply block and a superconducting block, wherein there are prepared a first sputtering target with a first material for the charge supply block and a second sputtering target with a material for the superconducting block, to form on a substrate alternately a first and a second block constituting said charge supply and superconducting block, respectively by sputtering from said first and second targets in alternate sputtering operations each controllably so that each of said first and second block has a film thickness determined for the corresponding one of said charge supply and superconducting block in said basic unit cell, characterized in that said process control program comprises input data for respective sputtering power magnitudes for said sputtering targets, rate(s) of rotation and temperature(s) of said substrate, gas flow rate(s) and pressure(s), degree(s) of vacuum, respective rates of deposition of said block on said substrate from said target materials and respective time periods for deposition of said block on said substrate determined from the respective thicknesses of said block in said basic unit cell, and respective numbers of repetition of said sputtering operations needed corresponding to a desired thickness of said composite oxide thin film, and said input data are enterable into a computer to have the computer communicate with terminal computers associated, respectively, with a plurality of sputtering power supply units, a substrate holding, rotating and heating unit, shutters and their respective rotation control units, a gas flow rate and pressure control unit, and a plurality of evacuating units to control respective operations of these units.