Process and material for semiconductor photomask fabrication

In a plasma process for chemically etching metallic material in the presence of organic material without significant degradation of the organic material, the improvement comprising the step of:

• exposing the material to a gaseous low temperature plasma to form volatile oxychloride derivatives as products within the temperature range 25.degree. to 350.degree. Centigrade and wherein said gaseous low temperature plasma is formed from a mixture of oxygen and a halocarbon vapor or gas having no more than two carbon atoms per molecule, wherein at least one carbon atom in said molecule is linked to a predominance of chlorine atoms.

A composition of matter useful for chemically converting material in a plasma environment comprised of a mixture of oxygen and halogen containing gas selected from one of the following groups, chlorine gas, inorganic chlorine containing compounds capable of forming volatile oxychloride derivatives as products within the temperature range 25.degree. to 350.degree. Centigrade, and a halocarbon vapor or gas having no more than two carbon atoms per molecule, wherein at least one carbon atom in said molecule is linked to a predominance of chlorine atoms, wherein said mixture contains 25 to 80% oxygen by volume.

A composition of matter, useful for chemically converting material in a plasma environment, comprised of a binary gaseous mixture of oxygen and a halocarbon having no more than two carbon atoms per molecule, wherein at least one carbon atom in said molecule is linked to a predominance of chlorine atoms, and wherein said mixture contains 25 to 80% oxygen by volume.

A composition of matter, useful in a process for chemically converting material by forming oxychloride-based compounds volatile in a low pressure, low temperature plasma, comprise of a ternary gaseous mixture of oxygen, ethylene trichloride, and carbon tetrachloride, and wherein said mixture contains 25% to 80% oxygen by volume.

A composition of matter, useful in a process for chemically converting material by forming oxychloride-based compounds volatile in a low pressure, low temperature plasma, comprised of a ternary gaseous mixture of oxygen, ethylene trichloride, and trichlorofluoromethane, and wherein said mixture contains 25% to 80% oxygen by volume.

A composition of matter, useful in a process for chemically converting material by forming oxychloride-based compounds volatile in a low pressure, low temperature plasma, comprised of a ternary gaseous mixture of oxygen, carbon tetrachloride, and trichlorofluoromethane, and wherein said mixture contains 25% to 80% oxygen by volume.

A composition of matter, useful in a process for chemically converting material by forming oxychloride based compounds volatile in a low pressure, low temperature plasma, comprised of a ternary gaseous mixture of oxygen, carbon tetrachloride and 1, 1, 2-trichloro-1, 2, 2-trifluoroethane, and wherein said mixture contains 25% to 80% oxygen by volume.

A composition of matter useful in a process for chemically converting material by forming oxychloride based compounds volatile in a low pressure, low temperature plasma comprised of a ternary gaseous mixture of oxygen, ethylene trichloride and 1, 1, 2-trichloro-1, 2, 2-trifluoroethane, and wherein said mixture contains 25% to 80% oxygen by volume.

A composition of matter useful in a process for chemically converting material by forming oxychloride based compounds volatile in a low pressure, low temperature plasma comprised of a ternary gaseous mixture of oxygen, trichlorofluoromethane and 1, 1, 2-trichloro-1, 2, 2-trifluoroethane, and wherein said mixture contains 25% to 85% oxygen by volume.

In a plasma process for etching metallic material in the presence of an organic etch mask without significant degradation of the organic etch mask, the improvement comprising;

• the step of exposing the material and the organic etch mask to a low temperature, low pressure gaseous plasma to form volatile oxychloride derivatives as products within the temperature range 25.degree. to 350.degree. Centigrade and wherein the low pressure gaseous plasma is formed from a mixture of oxygen and a halogen containing gas selected from one of the following groups, chlorine gas, inorganic chlorine compounds capable of forming volatile oxychloride derivatives as products within the temperature range 25.degree. to 350.degree. Centigrade, and a halocarbon vapor or gas having no more than two carbon atoms per molecule, wherein at least one carbon atom in said molecule is linked to a predominance of chlorine atoms.

A process for chemically converting materials in a plasma environment, comprising the step of exposing the material to a gaseous low pressure, low temperature plasma formed from a binary mixture of chlorine gas and oxygen wherein oxygen comprises between 40% and 80% of said mixture.

A process for chemically etching metallic materials in the presence of organic materials without significant degradation of the organic materials in a plasma environment comprising the step of:

• exposing the material to a low pressure, gaseous plasma formed from a binary mixture of oxygen and inorganaic chloride gas or vapor and thereby forming volatile oxychloride based compounds within the temperature range of 25.degree. to 350.degree. Centigrade.

A composition of matter, useful for chemically converting material in a plasma environment comprising, a binary mixture of oxygen and inorganic chloride gas, wherein said inorganic chloride gas comprises from 20% to 60% of said mixture.