US 12,243,605 B2
Storage system and method for proactive die retirement by fatal wordline leakage detection
Xuan Tian, Shanghai (CN); Liang Li, Shanghai (CN); Dandan Yi, Shanghai (CN); Jojo Xing, Shanghai (CN); Vincent Yin, Shanghai (CN); Yongke Sun, Shanghai (CN); and Alan Bennett, Edinburgh (GB)
Assigned to Sandisk Technologies, Inc., Milpitas, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jul. 1, 2022, as Appl. No. 17/856,073.
Prior Publication US 2024/0006010 A1, Jan. 4, 2024
Int. Cl. G11C 29/42 (2006.01); G11C 29/12 (2006.01); G11C 29/44 (2006.01)
CPC G11C 29/42 (2013.01) [G11C 29/1201 (2013.01); G11C 29/4401 (2013.01); G11C 2029/1202 (2013.01)] 10 Claims
OG exemplary drawing
 
1. In a storage system comprising a memory die, a method comprising:
detecting a grown bad block (GBB) in the memory die in response to detecting a wordline short;
performing fatal wordline leak detection on the detected grown bad block by independently biasing each wordline in the detected grown bad block to identify a location of the wordline short, wherein in performing the fatal wordline leak detection, at a given time, only two wordlines receive low and high biases from XY decode circuitry in a high-voltage switch and all other wordlines are floating;
in response to identifying the location of the wordline short as being in a memory array of the memory die, which corresponds to a success of the fatal wordline leak detection:
transferring data out of the detected grown bad block; and
retiring the detected grown bad block but not the memory die; and
in response to identifying the location of the wordline short as being in a peripheral wordline routing area of the memory die that is susceptible of a control gate interface (CGI) short, which corresponds to a failure of fatal wordline leak detection:
transferring data out of the detected grown bad block and other blocks in the memory die; and
retiring the memory die.