The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 23, 2025
Filed:
Jul. 27, 2023
Sandisk Technologies, Inc., Milpitas, CA (US);
Abhijith Prakash, Milpitas, CA (US);
Parth Amin, Livermore, CA (US);
Xiang Yang, Santa Clara, CA (US);
Sandisk Technologies, Inc., Milpitas, CA (US);
Abstract
Technology is disclosed herein for detecting evolved bad blocks in three-dimensional NAND. The test may include a drain side erase that includes applying an erase voltage from the bit lines and a source side erase that includes applying an erase voltage from the source line(s). If the source side erase performed worse than the drain side erase this may indicate a defect near the source side of the block. For example, the source side erase may fail but the drain side erase may pass. As another example the source side erase may take at least a pre-determined number of additional erase pulses to pass than the drain side erase. If the block is found as having a defect the entire block could be marked bad or the defective region could be identified such that the defective region is no longer used.