Etching solution for tungsten and GST films
Described herein is an etching solution suitable for both tungsten-containing metals and GST metals, which comprises: water; at least one phenolic derivative compound having at least two hydroxyl groups; at least one strong base selected from the group consisting of (i) a quaternary base; (ii) an organic amine; and (iii) a metal hydroxide; optionally an ammonium salt of an organic acid; and optionally a water-miscible solvent, wherein the pH of the etching solution is 10 or greater, and wherein the etching solution is substantially free of a peroxide oxidizer and a metal ion-containing oxidizer.
Versum Materials US, LLC
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C23F H01L C23F H01L H01L
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Wen Dar Laisheng Yi-Chia Gang Chris Tianniu
Liu Sun Lee Han-Adebekun Chen