Abstract: An alternating stack of first material layers and second material layers can be formed over a semiconductor material layer. A patterning film is formed over the alternating stack, and openings are formed through the patterning film. Via openings are formed through the alternating stack at least to a top surface of the semiconductor material layer by performing a first anisotropic etch process that transfers a pattern of the openings in the patterning film. A cladding liner can be formed on a top surface of the patterning film and sidewalls of the openings in the pattering film. The via openings can be vertically extended through the semiconductor material layer at least to a bottom surface of the semiconductor material layer by performing a second anisotropic etch process employing the cladding liner as an etch mask.

Abstract: A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate; forming an etch mask material layer containing an opening over the alternating stack; performing a first anisotropic etch process that etches unmasked upper portions of the alternating stack to form a via opening below the opening in the etch mask material layer; forming a combination of a non-conformal cladding liner and a conformal sacrificial spacer layer over the etch mask material layer and in peripheral portions of the via opening; performing a punch-through process that etches a horizontally-extending portion of the conformal sacrificial spacer layer from a bottom portion of the via opening; and vertically extending the via opening by performing a second anisotropic etch process that etches unmasked lower portions of the alternating stack selective to the non-conformal cladding liner and the conformal sacrificial spacer layer.

Abstract: A method includes forming an alternating stack of first material layers and second material layers, forming an etch mask material layer containing an opening over the alternating stack, forming a non-conformal cladding liner over the etch mask material layer, where the non-conformal cladding liner includes a horizontally extending portion that overlies a horizontal top surface of the etch mask material layer and a vertically extending portion contacting a sidewall of the opening in the etch mask material layer, implanting ions of dopant atoms into the non-conformal cladding line, and performing an second anisotropic etch process that etches an unmasked portion of the alternating stack selective to the etch mask material layer and the non-conformal cladding liner. The non-conformal cladding liner provides a higher etch resistance relative to the unmasked portion of the alternating stack after the step of implanting ions than before the step of implanting ions.

Abstract: A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate, forming a first etch mask material layer, forming a first cladding liner, and forming a via opening through the alternating stack by performing an anisotropic etch process that employs a combination of at least the first cladding liner and the first etch mask material layer as a composite etch mask structure.

Abstract: A method of forming a structure includes forming an alternating stack of first material layers and second material layers over a substrate, forming a mask layer over the alternating stack, forming a cavity in the mask layer, forming a first cladding liner on a sidewall of the cavity in the mask layer, and forming a via opening the alternating stack by performing an anisotropic etch process that transfers a pattern of the cavity in the mask layer through the alternating stack using a combination of the first cladding liner and the mask layer as an etch mask.

Abstract: A source-level semiconductor layer and an alternating stack of first material layers and second material layers is formed above a substrate. A hard mask layer is formed over the alternating stack, and is subsequently patterned to provide a pattern of cavities therethrough. Via openings are formed through the alternating stack by performing an anisotropic etch process. A cladding liner is formed on sidewalls of the cavities in the hard mask layer and on a top surface of the hard mask layer. The via openings are vertically extended at least through the source-level semiconductor layer by performing a second anisotropic etch process employing a combination of the cladding liner and the hard mask layer as an etch mask.

Abstract: A method includes forming an alternating stack of first and second layers, forming a composite hard mask layer over the alternating stack, forming openings in the hard mask, and forming via openings through the alternating stack by performing an anisotropic etch process that transfers a pattern of the openings in the composite hard mask layer through the alternating stack. The compositing hard mask includes a first cladding material layer which has higher etch resistance than upper and lower patterning films of the composite hard mask.

Abstract: An alternating stack of first material layers and second material layers can be formed over a semiconductor material layer. A patterning film is formed over the alternating stack, and openings are formed through the patterning film. Via openings are formed through the alternating stack at least to a top surface of the semiconductor material layer by performing a first anisotropic etch process that transfers a pattern of the openings in the patterning film. A cladding liner can be formed on a top surface of the patterning film and sidewalls of the openings in the pattering film. The via openings can be vertically extended through the semiconductor material layer at least to a bottom surface of the semiconductor material layer by performing a second anisotropic etch process employing the cladding liner as an etch mask.