Sandisk Technologies Inc.

Fabo Yu

Yanli Zhang

Jixin Yu

Chun Ge

Johann Alsmeier

Jayavel Pachamuthu

Tuan Duc Pham

Yao-Sheng Lee

Jongsun Sel

Kensuke Yamaguchi

Masanori Terahara

Shuji Minagawa

Cheng-Chung Chu

Xin Yuan Li

An alternating stack of insulating layers and spacer material layers is formed over a substrate. A staircase region having stepped surfaces is formed by patterning the alternating stack. Memory opening fill structures are formed in a memory array region, and support pillar structures are formed in the staircase region. Each of the memory stack structures includes a memory film and a vertical semiconductor channel. The support pillar structures include first support pillar structures and having a first maximum lateral dimension and second support pillar structures having a second maximum lateral dimension that is less than the first maximum lateral dimension and interlaced with the first support pillar structures. The sacrificial material layers are replaced with electrically conductive layers. The second support pillar structures are positioned interstitially among the first support pillar structures and contact via structures that are formed on the electrically conductive layers to provide additional structural support.

Three-dimensional memory device containing asymmetric, different size support pillars and method for making the same

After formation of an alternating stack of insulating layers and sacrificial material layers, a memory opening can be formed through the alternating stack, which is subsequently filled with a columnar semiconductor pedestal portion and a memory stack structure. Breakage of the columnar semiconductor pedestal portion under mechanical stress can be avoided by growing a laterally protruding semiconductor portion by selective deposition of a semiconductor material after removal of the sacrificial material layers to form backside recesses. At least an outer portion of the laterally protruding semiconductor portion can be oxidized to form a tubular semiconductor oxide spacer. Electrically conductive layers can be formed in the backside recesses to provide word lines for a three-dimensional memory device.

Three-dimensional memory device with enhanced mechanical stability semiconductor pedestal and method of making thereof

Memory openings and support openings can be formed through an alternating stack of insulating layers and sacrificial material layers. A set of dielectric layers and at least one semiconductor material layer can be sequentially deposited in each of the memory openings and the support openings. The at least one semiconductor material layer is removed from inside the support openings, while the at least one semiconductor material layer is not removed from inside the memory openings. Memory stack structures and support pillar structures are formed in the memory openings and the support openings, respectively. The sacrificial material layers are replaced with electrically conductive layers. Removal of the at least one semiconductor material layer from the support pillar structures reduces or eliminates leakage current through the support pillar structures.

Three-dimensional memory device with leakage reducing support pillar structures and method of making thereof

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San Ramon, CA, United States of America

Fabo Yu