Tungsten oxide processing
First Claim
1. A method of etching tungsten oxide, the method comprising:
- flowing a fluorine-containing precursor and ammonia (NH3) into a remote plasma region fluidly coupled to a substrate processing region via through-holes in a showerhead while forming a remote plasma in the remote plasma region to produce plasma effluents; and
etching the tungsten oxide from a substrate disposed within the substrate processing region by flowing the plasma effluents into the substrate processing region through the through-holes in the showerhead.
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Abstract
Methods of selectively etching tungsten oxide relative to tungsten, silicon oxide, silicon nitride and/or titanium nitride are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor in combination with ammonia (NH3). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten oxide. The plasmas effluents react with exposed surfaces and selectively remove tungsten oxide while very slowly removing other exposed materials. Increasing a flow of ammonia during the process removes a typical skin of tungsten oxide having higher oxidation coordination number first and then selectively etching lower oxidation tungsten oxide. In some embodiments, the tungsten oxide etch selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region.
853 Citations
15 Claims
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1. A method of etching tungsten oxide, the method comprising:
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flowing a fluorine-containing precursor and ammonia (NH3) into a remote plasma region fluidly coupled to a substrate processing region via through-holes in a showerhead while forming a remote plasma in the remote plasma region to produce plasma effluents; and etching the tungsten oxide from a substrate disposed within the substrate processing region by flowing the plasma effluents into the substrate processing region through the through-holes in the showerhead. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of etching tungsten oxide, the method comprising:
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flowing a fluorine-containing precursor and ammonia (NH3) into a remote plasma region fluidly coupled to a substrate processing region via through-holes in a showerhead, wherein the fluorine-containing precursor and the ammonia are flowed at a first flow rate ratio (ammonia;
fluorine-containing precursor);forming a remote plasma in the remote plasma region to produce plasma effluents from the fluorine-containing precursor and the ammonia (NH3); etching a first portion of the tungsten oxide from a substrate disposed within the substrate processing region by flowing the plasma effluents into the substrate processing region through the through-holes in the showerhead; increasing flow rate ratio (ammonia;
fluorine-containing precursor) to a second flow rate ratio which is greater than the first flow rate ratio;etching a second portion of the tungsten oxide from the substrate by continuing to flow plasma effluents into the substrate processing region. - View Dependent Claims (8, 9, 10, 11)
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12. A method of etching tungsten oxide, the method comprising:
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flowing nitrogen trifluoride (NF3) at a nitrogen trifluoride flow rate and ammonia (NH3) at a first ammonia flow rate into a remote plasma region fluidly coupled to a substrate processing region via through-holes in a showerhead; forming a remote plasma in the remote plasma region to produce plasma effluents from the nitrogen trifluoride and the ammonia; etching a first portion of the tungsten oxide from a substrate disposed within the substrate processing region by flowing the plasma effluents into the substrate processing region through the through-holes in the showerhead; increasing the flow rate of the ammonia from the first ammonia flow rate to a second ammonia flow rate; etching a second portion of the tungsten oxide from the substrate by continuing to flow plasma effluents into the substrate processing region. - View Dependent Claims (13, 14, 15)
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Specification