Process and material for manufacturing semiconductor devices

Abstract

A process step and material for use in the manufacture of semiconductor devices. To facilitate the etching of unmasked silicon dioxide, silicon nitride, silicon monoxide, bare silicon layers, or various refractory metals on preselected portions of a semiconductor slice, the material is exposed to a low pressure RF generated "cold" plasma (under 325° C.) produced from a homogeneous gaseous binary mixture of oxygen and a halocarbon. The halocarbon is preferably a gas having one carbon atom per molecule and is preferably fully fluorine-substituted.

What is claimed is: .[.1. A process for chemically converting material in a plasma environment, comprising the step of: 
     
        intermediate low order oxides..]. 2. A process for .Iadd.chemically .Iaddend.etching .Iadd.solid .Iaddend.material in a plasma environment comprising the step of: exposing the material to a gaseous plasma formed from a binary mixture consisting essentially of oxygen and a halocarbon having only one carbon atom per molecule, said carbon atom being linked to a predominance of   
     
     
        fluorine atoms to produce as an intermediate a low order oxide. 3. A process as in claim 2 wherein the reaction temperature is within the range 
     
     
        of 25 to 300 degrees centigrade. 4. A process as in claim 2 wherein said 
     
     
        halocarbon gas includes at least one hydrogen atom. 5. A process as in claim 2 wherein said halocarbon and said oxygen are supplied to a reactor 
     
     
        from separate sources. 6. A process as in claim 2 wherein said halocarbon and said oxygen are supplied to a reactor from a common premixed source. 
     
     
           A process as in claim 6 wherein said gaseous binary mixture contains 8.5 percent oxygen and 91.5 percent tetrafluoromethane by volume, said mixture being supplied to said reactor at a total flow rate within the range of 9 to 55 micromoles per second corresponding total pressures of 220 to 850 microns mercury, and having RF energy coupled to said mixture within the range of 20 to 400 watts. .[.8. A composition of matter, useful for chemically converting material in a plasma environment, consisting essentially 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 fluorine atoms..].   
     
     
           A composition of matter, useful in a process for .Iadd.chemically .Iaddend.etching .Iadd.a silicon containing .Iaddend.material in the presence of an organic etch mask by forming fluorine-based and oxyfluoride-based compounds volatile in a low pressure-low temperature plasma, consisting essentially of a binary gaseous mixture of oxygen and tetrafluoromethane wherein said mixture contains 1 to 25 percent oxygen by volume. .[.10. A composition of matter, useful in a process for etching material in the absence of an organic etch mask by forming fluorine-based and oxyfluoride-based compounds volatile in a low pressure-low temperature plasma, consisting essentially of a binary gaseous mixture of oxygen and tetrafluoromethane wherein said mixture contains 1 to 75 percent oxygen by volume..]. .[.11. A composition of matter, useful in a process for etching material in the presence of a metal etch mask by forming fluorine-based and oxyfluoride-based compounds volatile in a low pressure-low temperature plasma, consisting essentially of a binary gaseous mixture of oxygen and tetrafluoromethane wherein said mixture contains 1 to 75 percent oxygen by 
     
     
        volume..]. 12. A composition of matter, useful in a process for .Iadd.etching silicon oxide in the presence of photoresist in .Iaddend.manufacturing semiconductors, comprising a binary gaseous mixture of oxygen and tetrafluoromethane, said oxygen containing 8.5 percent of the mixture by volume. .Iadd. 13. A process for chemically etching solid material in a plasma environment, comprising the step of: exposing the material to a gaseous plasma at a pressure of at least 220 microns formed from a binary mixture consisting essentially 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 fluorine atoms to produce as an intermediate low order oxides. .Iaddend. .Iadd. 14. A process for chemically etching solid material in a plasma environment, comprising the step of:   exposing the material to a gaseous plasma formed in an RF field from a binary mixture consisting essentially 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 fluorine atoms to produce as an intermediate low order oxides. .Iaddend..Iadd. 15. A process for chemically etching solid material in a plasma environment, comprising the step of:   exposing the material to a gaseous plasma formed from a binary mixture consisting essentially 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 fluorine atoms to produce as an intermediate low order oxides and wherein said mixture contains 1 to 25% oxygen by volume. .Iaddend.