Invention Grant
- Patent Title: Three-dimensional NAND memory device with common bit line for multiple NAND strings in each memory block
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Application No.: US15948737Application Date: 2018-04-09
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Publication No.: US10355015B2Publication Date: 2019-07-16
- Inventor: Yanli Zhang , James Kai , Johann Alsmeier
- Applicant: SANDISK TECHNOLOGIES LLC
- Applicant Address: US TX Addison
- Assignee: SANDISK TECHNOLOGIES LLC
- Current Assignee: SANDISK TECHNOLOGIES LLC
- Current Assignee Address: US TX Addison
- Agency: The Marbury Law Group PLC
- Main IPC: G11C16/10
- IPC: G11C16/10 ; G11C16/26 ; H01L27/11582 ; H01L27/1157 ; G11C16/24 ; G11C16/04 ; H01L29/792 ; G11C16/08 ; H01L27/11575

Abstract:
A memory device includes an alternating stack of insulating layers and electrically conductive layers. Vertical NAND strings are formed through the alternating stack, each of which includes a drain region, memory cell charge storage transistors, and a pair of drain select transistors in a series connection. A common bit line is electrically connected to drain regions of two vertical NAND strings. The drain select transistors of the two vertical NAND strings are configured such that drain select transistors sharing a first common drain select gate electrode provide a higher threshold voltage for one of the two vertical NAND strings, and drain select transistors sharing a second common drain select gate electrode provide a higher threshold voltage for the other of the two vertical NAND strings. The different threshold voltages can be provided by a combination of a masked ion implantation and selective charge injection.
Public/Granted literature
- US20180233513A1 THREE-DIMENSIONAL NAND MEMORY DEVICE WITH COMMON BIT LINE FOR MULTIPLE NAND STRINGS IN EACH MEMORY BLOCK Public/Granted day:2018-08-16
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