Abstract: A vertical layer stack including a bit-line-level dielectric layer and an etch stop dielectric layer can be formed over an array region. Bit-line trenches are formed through the vertical layer stack. Bit-line-trench fill structures are formed in the bit-line trenches. Each of the bit-line-trench fill structures includes a stack of a bit line and a capping dielectric strip. At least one via-level dielectric layer can be formed over the vertical layer stack. A bit-line-contact via cavity can be formed through the at least one via-level dielectric layer and one of the capping dielectric strips. A bit-line-contact via structure formed in the bit-line-contact via cavity includes a stepped bottom surface including a top surface of one of the bit lines, a sidewall segment of the etch stop dielectric layer, and a segment of a top surface of the etch stop dielectric layer.

Abstract: A vertical layer stack including a bit-line-level dielectric layer and an etch stop dielectric layer can be formed over an array region. Bit-line trenches are formed through the vertical layer stack. Bit-line-trench fill structures are formed in the bit-line trenches. Each of the bit-line-trench fill structures includes a stack of a bit line and a capping dielectric strip. At least one via-level dielectric layer can be formed over the vertical layer stack. A bit-line-contact via cavity can be formed through the at least one via-level dielectric layer and one of the capping dielectric strips. A bit-line-contact via structure formed in the bit-line-contact via cavity includes a stepped bottom surface including a top surface of one of the bit lines, a sidewall segment of the etch stop dielectric layer, and a segment of a top surface of the etch stop dielectric layer.

Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a semiconductor material layer. Memory stack structures are formed through the alternating stack. A backside trench is formed through the alternating stack. The sacrificial material layers are replaced with electrically conductive layers. An insulating spacer is formed on sidewalls of the backside trench. A first doped semiconductor material is deposited within the backside trench. Vertical cavities are formed by vertically recessing the first doped semiconductor material at discrete locations that are laterally spaced apart. A second doped semiconductor material is deposited in the vertical cavities. The second doped semiconductor material disrupts a laterally-extending cavity in the first doped semiconductor material, thereby providing a structurally reinforced network of the first and second doped semiconductor materials for a backside contact via structure that is formed in the backside trench.

Abstract: A three-dimensional memory device includes a pair of alternating stacks of insulating layers and electrically conductive layers located over a semiconductor region, and laterally spaced from each other by a backside trench, memory stack structures extending through the pair of alternating, each memory stack structure containing a vertical semiconductor channel and a memory film, and a backside contact assembly located in the backside trench. The backside contact assembly includes an isolation dielectric spacer contacting the pair of alternating stacks, a conductive liner contacting inner sidewalls of the isolation dielectric spacer and a top surface of the semiconductor region, and composite non-metallic core containing at least one outer dielectric fill material portion that is laterally enclosed by a lower portion of the conductive liner and a dielectric core contacting an inner sidewall of the at least one outer dielectric fill material portion.

Abstract: A three-dimensional memory device includes a pair of alternating stacks of insulating layers and electrically conductive layers located over a semiconductor region, and laterally spaced from each other by a backside trench, memory stack structures extending through the pair of alternating, each memory stack structure containing a vertical semiconductor channel and a memory film, and a backside contact assembly located in the backside trench. The backside contact assembly includes an isolation dielectric spacer contacting the pair of alternating stacks, a conductive liner contacting inner sidewalls of the isolation dielectric spacer and a top surface of the semiconductor region, and composite non-metallic core containing at least one outer dielectric fill material portion that is laterally enclosed by a lower portion of the conductive liner and a dielectric core contacting an inner sidewall of the at least one outer dielectric fill material portion.

Abstract: An alternating stack of insulating layers and sacrificial material layers is formed over a semiconductor material layer. Memory stack structures are formed through the alternating stack. A backside trench is formed through the alternating stack. The sacrificial material layers are replaced with electrically conductive layers. An insulating spacer is formed on sidewalls of the backside trench. A first doped semiconductor material is deposited within the backside trench. Vertical cavities are formed by vertically recessing the first doped semiconductor material at discrete locations that are laterally spaced apart. A second doped semiconductor material is deposited in the vertical cavities. The second doped semiconductor material disrupts a laterally-extending cavity in the first doped semiconductor material, thereby providing a structurally reinforced network of the first and second doped semiconductor materials for a backside contact via structure that is formed in the backside trench.

Abstract: Collateral etching of a dielectric material around a trench during formation of a substrate contact via structure can be avoided employing an aluminum oxide layer. The aluminum oxide layer functions as an etch stop layer during an anisotropic etch that removes horizontal portions of an insulating material layer to form an insulating spacer. The aluminum oxide layer may be a conformal or a non-conformal material layer, and may, or may not, include a horizontal portion that overlies an alternating stack of insulating layers and electrically conductive layers. Electrical shorts caused by widening of the top portion of the trench can be avoided through use of the aluminum oxide layer. Memory stack structures can extend through the alternating stack to provide a three-dimensional memory stack structure. A source region can be formed underneath the trench, and the substrate contact via structure can be employed as a source contact via structure.

Abstract: Collateral etching of a dielectric material around a trench during formation of a substrate contact via structure can be avoided employing an aluminum oxide layer. The aluminum oxide layer functions as an etch stop layer during an anisotropic etch that removes horizontal portions of an insulating material layer to form an insulating spacer. The aluminum oxide layer may be a conformal or a non-conformal material layer, and may, or may not, include a horizontal portion that overlies an alternating stack of insulating layers and electrically conductive layers. Electrical shorts caused by widening of the top portion of the trench can be avoided through use of the aluminum oxide layer. Memory stack structures can extend through the alternating stack to provide a three-dimensional memory stack structure. A source region can be formed underneath the trench, and the substrate contact via structure can be employed as a source contact via structure.

Abstract: A contact via cavity can be filled with a lower structure and an upper structure. The lower structure can be a conductive structure that is formed by depositing a conformal conductive material, and subsequently removing an upper portion of the conformal conductive material. A disposable material portion can be formed at a bottom of the cavity to protect the bottom portion of the conformal conductive layer during removal of the upper portion. After removal of the disposable material, at least one conductive material can fill the remainder of the cavity to form the upper structure. The upper structure and the lower structure collectively constitute a contact via structure. Alternatively, the lower structure can be a dielectric spacer with an opening therethrough. The upper structure can be a conductive structure that extends through the dielectric spacer, and provides an electrically conductive vertical connection.

Abstract: A contact via cavity can be filled with a lower structure and an upper structure. The lower structure can be a conductive structure that is formed by depositing a conformal conductive material, and subsequently removing an upper portion of the conformal conductive material. A disposable material portion can be formed at a bottom of the cavity to protect the bottom portion of the conformal conductive layer during removal of the upper portion. After removal of the disposable material, at least one conductive material can fill the remainder of the cavity to form the upper structure. The upper structure and the lower structure collectively constitute a contact via structure. Alternatively, the lower structure can be a dielectric spacer with an opening therethrough. The upper structure can be a conductive structure that extends through the dielectric spacer, and provides an electrically conductive vertical connection.