Patent GB-1104935-A (GB)
Title: Improvements in or relating to a method of forming a layer of an inorganic compound
Inventor: STERLING HENRY FRANK
IPC: C23C16/34
Filed: 1964-05-08
Abstract: In depositing upon a surface of a substrate a coherent solid layer of an inorganic compound, the energy necessary to promote the required chemical reactions for the formation of the layer is provided by a plasma established adjacent to the surface in an atmosphere which contains all the elements of the inorganic compound layer to be deposited with at least one of the inorganic compound layer elements being present in the atmosphere as (i) an inorganic compound other than the inorganic compound to be deposited when the inorganic compound layer to be deposited does not contain carbon and (ii) as an organic compound when the inorganic compound layer to be deposited does include carbon, the remaining inorganic compound layer element or elements being present in the atmosphere other than as an organic compound or compounds when the inorganic compound layer to be deposited does not contain carbon, and wherein the substrate surface is at a temperature below that at which thermal decomposition of the atmosphere occurs.  Inorganic compounds include CO2 and carbides. Organic compounds include metal carbonyls.  Plasma is defined as a state within a gas in which there are substantially equal numbers of positively and negatively charged particles, the positive particles being ions, either atomic or molecular, and the negative particles being electrons.  The plasma may be established by applying a voltage which alternates at radio frequency and may exhibit glow discharge. Use of direct current for establishing a plasma is referred to.  The drawings (not shown) illustrate control of plasma by magnets (10, 22).  Substrates may be unheated, heated or cooled to obtain glassy amorphous or crystalline deposited layers.  Deposition may be at any pressure, e.g. 0.1-1 torr. The substrate may be a glass microscope slide, a strip or sheet of plastics film, a liquid Hg surface, an optical element such as a lens or prism, the surface of a semi-conductor device, a metal plate or body such as Mo, a polished Si slice or a plastics body.  Specified layer materials (1) to be deposited and starting materials (s) are <TABS:1104935/C6-C7/1> SiO2 may be applied to lenses or prisms of glass or other material for surface protection.  Si3N4 layers may be laid down at 700 to 900 DEG C. or be subsequently heated to such. They may be used as dielectric material in capacitors or to provide protective surfaces to plastics domestic items transistors or optical elements.  Borosilicate glass layers may be used in the formation of insulating layers on metallic surfaces, e.g. in micro-circuit manufacture, use as a capacitor dielectric material, and surface protection of semi-conductor devices.  Selective deposition of any of the layers may be obtained by the use of "in-contact" masks, e.g. of metal.ALSO:In depositing upon a surface of a substrate a coherent solid layer of an inorganic compound, the energy necessary to promote the required chemical reactions for the formation of the layer is provided by a plasma established adjacent to the surface in an atmosphere which contains all the elements of the inorganic compound layer to be deposited with at least one of the inorganic compound layer elements being present in the atmosphere as (i) an inorganic compound other than the inorganic compound to be deposited when the inorganic compound layer to be deposited does not contain carbon and (ii) as an organic compound when the inorganic compound layer to be deposited does include carbon, the remaining inorganic compound layer element or elements being present in the atmosphere other than as an organic compound or compounds when the inorganic compound layer to be deposited does not contain carbon, and wherein the substrate surface is at a temperature below that at which thermal decomposition of the atmosphere occurs.  Inorganic compounds include CO2 and carbides. Organic compounds include metal carbonyls. Plasma is defined as a state within a gas in which there are substantially equal numbers of positively and negatively charged particles, the positive particles being ions, either atomic or molecular, and the negative particles being electrons.  The plasma may be established by applying a voltage which alternates at radio frequency and may exhibit glow discharge. Use of direct current for establishing a plasma is referred to.  The drawings (not shown) illustrate control of plasma by magnets (10,22). Substrates may be unheated, heated or cooled to obtain glassy amorphous or crystalline deposited layer.  Deposition may be at any pressure, e.g. 0.1-1 torr.  The substrate may be a glass microscope slide, a strip or sheet of plastics film, a liquid Hg surface, an optical element such as a lens or prism, the surface of a semi-conductor device, a metal plate or body such as Mo, a polished Si slice or a plastics body. Specified layer materials (l) to be deposited and starting material(s) are:- <TABS:1104935/C1/1> SiO2 may be applied to lenses or prisms of glass or other material for surface protection.  Si3N4 layers may be laid down at 700 DEG  to 900 DEG  C. or be subsequently heated to such. They may be used as dielectric material in capacitors or to provide protective surfaces to plastics domestic items, transistors or optical elements.  Borosilicate glass layers may be used in the formation of insulating layers on metallic surfaces, e.g. in micro-circuit manufacture, use as a capacitor dielectric material, and surface protection of semi-conductor devices.  Selective deposition of any of the layers may be obtained by the use of "in-contact" masks, e.g. of metal.ALSO:In depositing upon a surface of a substrate a coherent solid layer of an inorganic compound, the energy necessary to promote the required chemical reactions for the formation of the layer is provided by a plasma established adjacent to the surface in an atmosphere which contains all the elements of the inorganic compound layer to be deposited with at least one of the inorganic compound layer elements being present in the atmosphere as (i) an inorganic compound other than the inorganic compound to be deposited when the inorganic compound layer to be deposited does not contain carbon and (ii) as an organic compound when the inorganic compound layer to be deposited does include carbon, the remaining inorganic compound layer element or elements being present in the atmosphere other than as an organic compound or compounds when the inorganic compound layer to be deposited does not contain carbon, and wherein the substrate surface is at a temperature below that at which thermal decomposition of the atmosphere occurs.  Inorganic compounds include CO2 and carbides. Organic compounds include metal carbonyls.  Plasma is defined as a state within a gas in which there are substantially equal numbers of positively and negatively charged particles, the positive particles being ions, either atomic or molecular, and the negative particles being electrons.  The plasma may be established by applying a voltage which alternates at radio frequency and may exhibit glow discharge. Use of direct current for establishing a plasma is referred to.  The drawings (not shown) illustrate control of plasma by magnets (10, 22).  Substrates may be unheated, heated or cooled to obtain glassy amorphous or crystalline deposited layers.  Deposition may be at any pressure, e.g. 0.1-1 torr.  The substrate may be a glass microscope slide, a strip or sheet of plastics film, a liquid Hg surface, an optical element such as a lens or prism, the surface of a semiconductor device, a metal plate or body such as Mo, a polished Si slice or a plastics body.  Specified layer materials (1) to be deposited and starting materials (s) are:- <TABS:1104935/B1-B2/1> SiO2 may be applied to lenses or prisms of glass or other material for surface protection.  Si3N4 layers may be laid down at 700 to 900 DEG C or be subsequently heated to such.  They may be used as dielectric material in capacitors or to provide protective surfaces to plastics domestic items transistors or optical elements. Borosilicate glass layers may be used in the formation of insulating layers on metallic surfaces, e.g. in micro-circuit manufacture, use as a capacitor dielectric material, and surface protection of semiconductor devices.  Selective deposition of any of the layers may be obtained by the use of "in-contact" masks, e.g. of metal.