Invention Grant
US08902668B1 Double verify method with soft programming to suppress read noise
有权
使用软编程的双重验证方法来抑制读取噪声
- Patent Title: Double verify method with soft programming to suppress read noise
- Patent Title (中): 使用软编程的双重验证方法来抑制读取噪声
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Application No.: US14053856Application Date: 2013-10-15
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Publication No.: US08902668B1Publication Date: 2014-12-02
- Inventor: Deepanshu Dutta , Ken Oowada , Genki Sano , Masaaki Higashitani
- Applicant: SanDisk Technologies Inc.
- Applicant Address: US TX Plano
- Assignee: SanDisk Technologies Inc.
- Current Assignee: SanDisk Technologies Inc.
- Current Assignee Address: US TX Plano
- Agency: Vierra Magen Marcus LLP
- Main IPC: G11C16/34
- IPC: G11C16/34 ; G11C16/10 ; G11C7/08 ; G11C16/26 ; G11C16/04

Abstract:
Memory cells which have read noise are identified during a programming pass and an amount of programming is increased for noisy memory cells compared to non-noisy cells. The read noise is indicated by a decrease in the threshold voltage of a cell when the cell is repeatedly read. During the programming pass, a cell enters a temporary lockout state when it passes a first verify test. In this state, the cell is subject to one or more additional verify tests. If the one or more additional verify tests indicate that the threshold voltage of a cell has decreased, the cell is noisy and is soft programmed before being permanently locked out. In contrast, programming of a non-noisy cell is concluded after the first verify test without further programming.
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