Apparatuses systems and methods for hot electron induced punch-through degradation mitigation
AssigneeMicron Technology, Inc.
InventorErik T. Barmon
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Abstract
A memory device undergoes hot electron induced punch-through (HEIP) degradation in the transistors of its sub-word line drivers. The memory device may identify sets of sub-word line drivers which have undergone HEIP degradation. For example, the memory may include a register which stores FX addresses and count values. When the row decoder provides a row address, the FX portion of the row address is compared to the stored FX addresses. If there is a match, the count value is updated. Once the updated count value crosses a threshold, the associated stored FX address is identified for HEIP refreshing. The memory may perform HEIP refreshes by activating the word lines which share the FX address in common.
Claims28
An apparatus comprising:
- a memory array comprising a plurality of word lines;
- a plurality of sub-word line drivers each coupled to a respective one of the plurality of word lines, wherein sets of the sub-word line drivers are coupled to a common FX driver signal, wherein the FX signal is associated with an FX address;
- and
- a refresh control circuit comprising a register configured to store a plurality of stored FX addresses and a plurality of count values each associated with one of the FX signals, wherein the refresh control circuit is configured to perform hot-electron induced punch-through (HEIP) refresh operations on sub-word line drivers of a selected one of the sets of the sub-word line drivers when one of the plurality of count values crosses a threshold.
A method comprising:
- receiving an FX address portion of a row address;
- comparing the FX address to a plurality of stored FX addresses in a register;
- updating a count value associated with one of the stored FX addresses if the one of the stored FX addresses matches the FX address;
- comparing the updated count value to a threshold;
- and
- performing one or more hot electron induced punch-through (HEIP) refresh operations on sub-word line drivers associated with the matching FX address if the updated count value crosses the threshold.
An apparatus comprising:
- a memory array comprising a plurality of word lines;
- a plurality of sub-word line drivers, each coupled to one of the plurality of word lines, wherein sets of the plurality of sub-word line drivers are coupled to a respective one of a plurality of FX signals;
- and
- a refresh control circuit configure to perform hot electron induced punch-through (HEIP) refresh operations by activating each of the plurality of sub-word line drivers associated with a selected one of the plurality of FX signals for a period of time each.
A method comprising:
- generating a sequence of hot electron induced punch-through (HEIP) refresh addresses, wherein each of the sequence of HEIP refresh addresses share an FX portion in common;
- and
- performing an HEIP refresh operation by activating a word line associated with one of the sequence of HEIP refresh addresses for a period of time.
An apparatus comprising:
- a p-type transistor;
- a hot electron induced punch-through (HEIP) tracking circuit configured to determine if the p-type transistor has undergone HEIP degradation;
- and
- a HEIP mitigation circuit configured to activate the p-type transistor identified as having undergone HEIP degradation for a period of time as part of a HEIP refresh operation.
Dependencies are inferred from the claim text.