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AssigneeAdvanced Technology Materials, Inc.
InventorsMichael B. Korzenski, Thomas H. Baum, Chongying Xu, Eliodor G. Ghenciu
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A method and composition for removing silicon-containing sacrificial layers from Micro Electro Mechanical System (MEMS) and other semiconductor substrates having such sacrificial layers is described. The etching compositions include a supercritical fluid (SCF), an etchant species, a co-solvent, and optionally a surfactant. Such etching compositions overcome the intrinsic deficiency of SCFs as cleaning reagents, viz., the non-polar character of SCFs and their associated inability to solubilize polar species that must be removed from the semiconductor substrate. The resultant etched substrates experience lower incidents of stiction relative to substrates etched using conventional wet etching techniques.
A supercritical fluid (SFC)-based composition, comprising at least one co-solvent, at least one etchant species, and optionally at least one surfactant, wherein said at least one etchant comprises an alkyl phosphonium difluoride ((R)4PNF2), where R is a C1–C4 alkyl group, and wherein said SFC-based composition is useful for etching sacrificial silicon-containing layers.
A method of removing silicon-containing substances from a substrate having same thereon, said method comprising contacting the substrate with a SCF-based composition comprising at least one co-solvent, at least one etchant species, and optionally at least one surfactant, for sufficient time and under sufficient contacting conditions to remove the silicon-containing substances from the substrate, wherein said at least one etchant comprises an alkyl phosphonium difluoride ((R)4PHF2), where R is a C1–C4 alkyl group.
Dependencies are inferred from the claim text.