Sandisk Technologies Inc.

Eisuke Takii

Kiyohiko Sakakibara

Yusuke Ikawa

Raghuveer S Makala

Hiroyuki Ogawa

Rahul Sharangpani

Fei Zhou

Senaka Kanakamedala

Masanori Tsutsumi

Akio Nishida

Seiji Shimabukuro

Somesh Peri

Kazutaka Yoshizawa

Kengo Kajiwara

Akira Matsudaira

Tomoyuki Obu

Keerti Shukla

Yu Ueda

Yasuyuki Aoki

Hiraku Hashimoto

Shin Koyama

A semiconductor structure includes semiconductor devices located on a top surface of a substrate semiconductor layer, lower-level metal interconnect structures, source-level material layers, and a three-dimensional memory array including an alternating stack of insulating layers and electrically conductive layers and memory stack structures vertically extending through the alternating stack and comprising a respective vertical semiconductor channel and a respective memory film. A vertically alternating sequence of insulating plates and dielectric material plates is laterally surrounded by the alternating stack. A through-memory-level interconnection via structure vertically extends through each plate within the vertically alternating sequence and contacts a center portion of a top surface of one of the lower-level metal interconnect structures. At least one silicon nitride liner prevents or reduces oxidation of the lower-level metal interconnect structures underneath the through-memory-level interconnection via structure.

Three-dimensional memory device containing oxidation-resistant contact structures and methods of making the same

A first field effect transistor and a second field effect transistor are formed on a substrate. A silicon nitride liner is formed over the first field effect transistor and the second field effect transistor. An upper portion of the silicon nitride liner is converted into a thermal silicon oxide liner. A lower portion of the silicon nitride liner remains as a silicon nitride material portion. A first portion of the thermal silicon oxide liner is removed from above the second field effect transistor, and a second portion of the thermal silicon oxide liner remains above the first field effect transistor. Selective presence of the silicon oxide liner provides differential stress within the channels of the first and second field effect transistors, which can be employed to optimize performance of different types of field effect transistors.

Field effect transistors having different stress control liners and method of making the same

A memory opening can be formed through an alternating stack of insulating layers and sacrificial material layers provided over a substrate. Annular etch stop material portions are provided at each level of the sacrificial material layers around the memory opening. The annular etch stop material portions can be formed by conversion of surface portions of the sacrificial material layers into dielectric material portion, or by recessing the sacrificial material layers around the memory opening and filling indentations around the memory opening. After formation of a memory stack structure, the sacrificial material layers are removed from the backside. The annular etch stop material portions are at least partially converted to form charge trapping material portions. Vertical isolation of the charge trapping material portions among one another around the memory stack structure minimizes leakage between the charge trapping material portions located at different word line levels.

Three-dimensional memory device containing vertically isolated charge storage regions and method of making thereof

Threshold voltage shift due to programming of a neighboring memory element can be reduced or suppressed by forming a compositionally modulated charge storage layer in a three-dimensional memory device. The compositionally modulated charge storage layer can be formed by providing an oxygen-containing dielectric silicon compound layer outside a tunneling dielectric layer, and subsequently nitriding portions of the oxygen-containing dielectric silicon compound layer only at levels of the control gate electrodes. An alternating stack of sacrificial material layers and insulating layers can be employed to form a memory stack structure therethrough. After removal of the sacrificial material layers, a nitridation process can be performed to convert physically exposed portions of the oxygen-containing dielectric silicon compound layer into silicon nitride portions, which are vertically spaced from one another by remaining oxygen-containing dielectric silicon compound portions that have inferior charge trapping property to the silicon nitride portions.

Locally-trap-characteristic-enhanced charge trap layer for three-dimensional memory structures

Corner rounding of electrically conductive layers in a replacement electrode integration scheme can be alleviated by employing compositionally modulated sacrificial material layers. An alternating stack of insulating layers and compositionally modulated sacrificial material layers can be formed over a substrate. Each of the compositionally modulated sacrificial material layers has a vertical modulation of material composition such that each compositionally modulated sacrificial material layer provides greater resistance to conversion into a silicon-oxide-containing material at upper and lower portions thereof than at a middle portion thereof during a subsequent oxidation process. Bird's beak features can be formed with lesser dimensions, and electrically conductive layers formed by replacement of remaining portions of the sacrificial material layers with a conductive material can have less corner rounding. Reduction in corner rounding can increase effectiveness of the control gates for a three-dimensional memory device.

Method of reducing control gate electrode curvature in three-dimensional memory devices

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Yokkaichi, Japan

Eisuke Takii