79 results about "Row hammer" patented technology

A semiconductor device according to an aspect of the present invention has: a plurality of memory cells MC; a plurality of word lines WL each coupled to a corresponding one of the plurality of memory cells MC; and a control circuit that intermittently monitors accesses to the plurality of word lines WL, stores/erases some captured row-addresses in a first number of registers, and detects, by comparison with stored addresses, in response to a first number of accesses to one of the word lines WL in a first period of time. According to the present invention, access histories can be precisely analyzed by a small-scale circuit configuration, and measures against, for example, the Row Hammer problem, etc. can be taken.

A memory controller to implement targeted refreshes of potential victim rows of a row hammer event. In an embodiment, the memory controller receives an indication that a specific row of a memory device is experiencing repeated accesses which threaten the integrity of data in one or more victim rows physically adjacent to the specific row. The memory controller accesses default offset information in the absence of address map information which specifies an offset between physically adjacent rows of the memory device. In another embodiment, the memory controller determines addresses for potential victim rows based on the default offset information. In response to the received indication of the row hammer event, the memory controller sends for each of the determined plurality of addresses a respective command to the memory device, where the commands are for the memory device to perform targeted refreshes of potential victim rows.

A smart refresh device includes an address control block configured to determine whether a specific row address is a row hammer address, and invert a first row hammer address and perform an addition/subtraction of an address; a repair control block configured to determine whether the row hammer address is a repaired address and output a stored repair address as a second repair control signal; a repair address storage block configured to store an output address of the address control block and output a stored address as a latch address; a fuse block configured to output a repair signal representing information on a repair address to the repair control block, and output a decoding signal according to the latch address; and an operator configured to add and subtract the decoding signal according to an addition signal and a subtraction signal.

Techniques and mechanisms for determining a count of accesses to a row of a memory device. In an embodiment, the memory device includes a counter comprising circuitry to increment a value of the count in response to detecting a command to activate the row. Circuitry of counter may further set a value of the count to a baseline value in response to detecting a command to refresh the row. In another embodiment, the memory device includes evaluation logic to compare a value of the count to a threshold value. A signal is generated based on the comparison to indicate whether a row hammer event for the row is indicated.

A refresh control device and a semiconductor device including the same, for preventing a row hammer failure from occurring, may include an enable signal generator configured to generate an enable signal for performing a smart refresh operation and a plurality of active controllers configured to generate a plurality of refresh signals for refreshing word lines located at different positions within one bank, based on receiving the enable signal.

An integrated circuit includes an aggressor wordline cache and logic that determines a candidate upper adjacent address and a candidate lower adjacent address of a target memory row corresponding to a read request to memory. When at least one of the candidate upper adjacent address or the candidate lower adjacent address are determined to be a victim row, the logic checks the aggressor wordline cache for a cache hit for the target memory row. When there is a cache hit in the aggressor wordline cache, the logic sends a corresponding cache line as a response to the read request, otherwise the logic causes a read of content from the memory. In certain examples, the logic includes a stored bit array and a hash function-based filter, which determines whether any of the candidate upper adjacent address and the candidate lower adjacent address are victim rows represented in the stored bit array.

A method and apparatus for implementing row hammer avoidance in a dynamic random access memory (DRAM) in a computer system. Hammer detection logic identifies a hit count of repeated activations at a specific row in the DRAM. Monitor and control logic receiving an output of the hammer detection logic compares the identified hit count with a programmable threshold value. Responsive to a specific count as determined by the programmable threshold value, the monitor and control logic captures the address where a selected row hammer avoidance action is provided.

The invention relates to the technical field of semiconductors, in particular to a semiconductor structure. The semiconductor structure comprises a substrate having an active region defined by an isolation structure, embedded word lines extending in a first direction across the active region, an embedded bit line extending along at least part of the isolation structure with the extending directionintersected with the first direction, and an air gap positioned between the two adjacent embedded word lines. An embedded bit line is formed in an isolation structure, the bit line-unit coupling effect is reduced, the data sensing margin is improved, and moreover, an air gap is formed between the adjacent embedded word lines, and the dielectric constant of air is relatively small, so that the coupling effect of the adjacent embedded word lines can be reduced, the row hammering effect between the adjacent active regions is reduced, and the reliability of the semiconductor device is improved.

A semiconductor structure for preventing row hammering issue in DRAM cell is provided in the present invention. The structure includes a trench with a gate dielectric, an n-type work function metal layer, a TiN layer conformally formed within, and a buried word line filled in the trench.

A memory device comprises one or more bank(s), each bank comprising a plurality of DRAM memory rows, the memory device further comprising: an external access port configured to allow an external memory controller to activate and then access the memory rows of each bank; one or more internal processor(s) capable of activating and then accessing the memory rows of each bank; a logic for detecting triggering of the Row Hammer configured to monitor, for each bank, the activation commands from the external memory controller and from one or more internal processor(s), the logic for detecting triggering including memory storage and a logic for sending preventive refresh configured to implement a refresh operation for one or more of the adjacent rows of each identified row by emitting refresh requests instead of the periodic refresh requests generated by the external memory controller, delaying one or more of said periodic refresh requests.

A memory system includes: a memory device including a plurality of banks; and a memory controller suitable for: controlling an operation of the memory device, calculating row hammer information for each of the banks for each program having a command set requested from a host, and scheduling the banks based on the row hammer information for each of the banks corresponding to a specific program when the specific program is requested from the host.

A method of manufacturing buried word lines and isolating structures thereof comprises the following steps of forming a plurality of buried word lines inside a substrate, wherein the top of each buried word line is lower than the surface of the substrate; forming a mask structural layer inside a groove on each buried word line, making the mask structural layer protrude by removing a part of the structure so that side walls of the mask structural layer form distance pieces and a plurality of self-aligned grooves are further formed; removing substrate parts under the grooves in an etching way with the distance pieces and the mask structural layers as the etching masks so as to form a plurality of isolating structure grooves; and further forming isolating structures inside the isolating structure grooves. By means of the manufacturing method, interference (Row Hammer) among word lines can be effectively alleviated. Furthermore, the area of a contact zone inside an active region can be kept.

Present disclosure includes a system for preserving data in a volatile memory and a method thereof. The volatile memory comprises a plurality of refreshing units, and each of the refreshing units comprises a plurality of word lines for storing data. The system comprises an accessing unit. The accessing unit is configured to detect a row-hammer indication indicating a first word line is frequently accessed, wherein the accessing unit is configured to copy data stored in the first word line to a second word line when the row-hammer indication is detected on the first word line, wherein the data stored in the first and the second word lines are available to be selectively accessed.

The present disclosure provides a method. The method includes copying a data stored in memory cells associated with a normal word line subject to a row hammer effect into memory cells associated with a hot word line before a condition is satisfied, wherein the condition includes an access frequency of the normal word line reaching a threshold frequency; accessing, based on a logical address, the normal word line before the condition is satisfied; accessing, based on the logical address, the hot word line associated with the copied data only if the condition is satisfied; and accessing the data no longer from the normal word line only if the condition is satisfied.

A method and apparatus for implementing row hammer avoidance in a dynamic random access memory (DRAM) in a computer system. Hammer detection logic identifies a hit count of repeated activations at a specific row in the DRAM. Monitor and control logic receiving an output of the hammer detection logic compares the identified hit count with a programmable threshold value. Responsive to a specific count as determined by the programmable threshold value, the monitor and control logic captures the address where a selected row hammer avoidance action is provided.

A memory device and a data refreshing method of the memory device are provided. The memory device includes a memory array and a memory control circuit. The memory control circuit counts the number of access commands to generate a first count value and counts the number of refreshing commands to generate a second count value. If the first count value is equal to the second count value, the memory control circuit latches a memory bank address and a memory row address corresponding to the access commands to obtain a row hammer refreshing bank address and a row hammer refreshing row address. The memory control circuit performs a row hammer refreshing operation on a memory bank according to the row hammer refreshing bank address and the row hammer refreshing row address.

A semiconductor structure includes a substrate with a first conductivity type and a first doping concentration, an active area with its longitudinal axis extending along a first direction, a trench isolation structure contiguous with an end surface of the active area, a passing gate in the trench isolation structure and extending along a second direction that is not parallel with the first direction, and a localized doping region with a second conductivity type and a second doping concentration that is located on the end surface.

Systems and methods for detecting a row hammer in a memory comprising a plurality of memory cells arranged in a plurality of rows may include: a plurality of detection cells in a subject row of memory cells, the detection cells to be set to respective initial states and configured to transition to a state different from their initial states in response to activations of memory cells in an adjacent row of memory cells; a comparison circuit to compare current states of the detection cells with initial states of the detection cells and to determine whether any of the detection cells have a current state that is different from their corresponding initial states; and a trigger circuit to trigger a refresh of the memory cells in the subject row based on a detection of detection cells in the subject row having current states that are different from their corresponding initial states.