A failed erase operation is detected at a memory block of a memory device. Based on detecting the failed erase operation at the memory block, data on the memory block is destroyed using a data destruction algorithm that corrupts data stored by one or more cells of the block. The data on the memory block is verified to be destroyed. A passing data destruction status for the memory block is provided based on verifying the data on the memory block is destroyed.

A method of operating a storage system is provided. The storage system includes memory cells and a memory controller, wherein each memory cell is an m-bit multi-level cell (MLC), where m is an integer, and the memory cells are arranged in m pages. The method includes determining initial LLR (log likelihood ratio) values for each of the m pages, comparing bit error rates in the m pages, identifying a programmed state in one of the m pages that has a high bit error rate (BER), and selecting an assist-read threshold voltage of the identified page. The method also includes performing an assist-read operation on the identified page using the assist-read threshold voltage, determining revised LLR values for the identified page based on results from the assist-read operation, and performing soft decoding using the revised LLR values for the identified page and the initial LLR values for other pages.

A memory apparatus and method of operation is provided. The apparatus includes memory cells connected to word lines and bit lines and arranged in strings and configured to retain a threshold voltage. Each of the memory cells is configured to be erased in an erase operation occurring during an erase time period. A control circuit is configured to adjust at least a portion of the erase time period in response to determining the erase operation is a segmented erase operation and is resumed after being suspended. The control circuit applies an erase signal having a plurality of voltage segments temporally separated from one another during the erase time period to each of the strings while simultaneously applying a word line erase voltage to selected ones of the word lines to encourage erasing of the memory cells coupled to the selected ones of the word lines in the segmented erase operation.

A failed erase operation is detected at a memory block of a memory device. Based on detecting the failed erase operation at the memory block, data on the memory block is destroyed using a data destruction algorithm that corrupts data stored by one or more cells of the block. The data on the memory block is verified to be destroyed. A passing data destruction status for the memory block is provided based on verifying the data on the memory block is destroyed.

A semiconductor storage device includes a memory string and a row decoder configured to apply voltages to first to fourth select gate lines and first and second word lines connected to the memory string. A sequencer has first mode for erasing the entire memory string and a second mode for erasing just a portion of the memory string. In the first mode, a first voltage is applied to the bit line and the source line, a second voltage lower than the first voltage is applied to the first select gate line, a third voltage is applied to the second select gate line, a fourth voltage is applied to the third select gate line, a fifth voltage lower than the first voltage is applied to the fourth select gate line, and a sixth voltage lower than the first to fifth voltages is applied to the first and second word lines.

A semiconductor storage device includes a memory string and a row decoder configured to apply voltages to first to fourth select gate lines and first and second word lines connected to the memory string. A sequencer has first mode for erasing the entire memory string and a second mode for erasing just a portion of the memory string. In the first mode, a first voltage is applied to the bit line and the source line, a second voltage lower than the first voltage is applied to the first select gate line, a third voltage is applied to the second select gate line, a fourth voltage is applied to the third select gate line, a fifth voltage lower than the first voltage is applied to the fourth select gate line, and a sixth voltage lower than the first to fifth voltages is applied to the first and second word lines.

A failed erase operation is detected at a memory block of a memory device. Based on detecting the failed erase operation at the memory block, data on the memory block is destroyed using a data destruction algorithm that corrupts data stored by one or more cells of the block. The data on the memory block is verified to be destroyed. A passing data destruction status for the memory block is provided based on verifying the data on the memory block is destroyed.

The invention provides a storage structure and an erase method thereof, capable of performing an erase operation on a plurality of memory blocks. The storage structure includes: a first storage body, a second storage body, a third storage body, and a controller. Memory blocks are sequentially alternately stored in the first memory bank, the second memory bank, and the third memory bank, and the controller is configured to control each memory block to sequentially undergo a first process, a second process and a third process. The erase method includes: when the memory block Bi undergoes the third process, the memory block Bi+1 undergoes the second process, and the memory block Bi+2 undergoes the first process at the same time; where i∈[1, n−2]. Three adjacent blocks undergo the first process, the second process, and the third process simultaneously.

A storage array includes multiple wordlines of storage cells that can be selectively charged to an erase voltage or an inhibit voltage. Control logic associated with the storage array can perform erase verify in stages. On a first erase verify pass, the control logic can set wordlines of an erase block or subblock to a first erase voltage. On a second erase verify pass, the control logic can trigger a second erase verify pulse and set passing wordlines to an inhibit voltage, and failing wordlines to a second erase voltage higher than the first voltage. Inhibiting the already passing wordlines can reduce threshold voltage differences among the wordlines.

According to one embodiment, a memory system includes a first memory and a memory controller. The first memory is nonvolatile and includes a plurality of memory cell transistors, each of which stores data corresponding to a threshold voltage. The memory controller causes the first memory to execute a read operation to acquire data corresponding to the threshold voltage from the plurality of memory cell transistors on the basis of a result of comparison between the threshold voltage and a read voltage. The memory controller selects a first candidate value from among a plurality of candidate values for the read voltage in accordance with a degree of stress that affects the threshold voltage; and causes the first memory to execute the read operation using the first candidate value as the read voltage.