21 results about "Semiconductor memory" patented technology

Transistor bodies of semiconductor material located at a main surface of a semiconductor substrate between shallow trench isolations are provided with a rounded or curved upper surface. A floating gate electrode is arranged above said upper surface and electrically insulated from the semiconductor material by a tunnel dielectric having essentially the same tiny thickness throughout a primary tunnel area encompassing the area of curvature. The floating gate electrode may bridge the transistor body and is covered with a coupling dielectric provided for a control gate electrode, which forms part of a wordline.

A semiconductor memory device for reading or writing data from or to a memory cell includes at least one cell array having a plurality of memory cells for outputting a stored data to one of a bit line and a bit line bar in response to inputted address and command; at least one reference cell array for outputting a reference signal to the other of the bit line and the bit line bar; a precharge block for precharging the bit line and the bit line bar as a ground; and a sense amplifying block for sensing and amplifying the data by using a core voltage for operating the semiconductor memory device and a high voltage having a higher voltage level than the core voltage.

A bit line resetting signal is supplied to the gate of an nMOS transistor (or a precharge circuit) which connects a bit line with a precharge voltage line. The high-level voltage of the bit line resetting signal is retained at a first voltage during the precharge operation after a refresh operation, and is retained at a second voltage higher than the first voltage during the precharge operation after an access operation. In the precharge operation after the refresh operation, therefore, the second voltage is not used so that the current consumption of the generating circuit of the second voltage is reduced. Thus, it is possible to reduce the current consumption (or the standby current) during the standby period for which the internal refresh requests continuously occur.

A circuit and method for test mode entry of a semiconductor memory device are provided. In a method of entering a semiconductor memory device into a test mode, an internal clock is generated in response to an external clock when a first condition is satisfied. An address combination signal is generated based on a first address combination and the internal clock. The semiconductor memory device is entered into the test mode using the internal clock and the address combination signal.

An amplifier circuit includes an amplification unit and a back-bias voltage providing unit. The amplification unit amplifies input data. The back-bias voltage providing unit provides selectively back-bias voltages of different levels to the amplification unit in an initial operation period of the amplification unit and a period after the initial operation period.

On a silicon substrate 201, there are formed a silicon oxide 202, an adhesion layer 203 consisting of TiO₂, a lower electrode 204 consisting of Pt, a ferroelectric thin film 205, and an upper electrode 206 consisting of Pt. A portion of the ferroelectric thin film adjacent to the upper electrode 206 is formed from a compound with a composition formula of SrBi₂ (Ta_xNb_1-x)₂O₉ where x=0.7. A compound with a value x in the composition formula being greater than 0.7 is used for the portion of the ferroelectric thin film adjacent to the upper electrode 206, so as to generate an appropriate number of grain boundaries on the surface of the ferroelectric film 205, the grain boundaries enabling implementation of anchoring effect between the ferroelectric film 205 and the upper electrode 206, thereby achieving prevention of exfoliation of the upper electrode 206 from the ferroelectric film 205. Therefore, the semiconductor memory device is free from exfoliation of the upper electrode film from the dielectric film and has a good yield.

A positional information storage system stores and verifies positional information of a mobile terminal apparatus. The positional information storage system stores (i) the positional information, (ii) time information, and (iii) signature data that is generated by placing a digital signature on a combination of the time information and the positional information of the mobile terminal apparatus only if a user of the mobile terminal apparatus is successfully authenticated. The positional information storage system also verifies whether the signature data is authentic. With this construction, it is possible to authenticate a person carrying the mobile terminal apparatus, and to verify whether data to be stored in the memory has been tampered with.

A semiconductor memory device includes a substrate including a cell array region and a pad region, a stack structure disposed on the cell array region and the pad region of the substrate and including gate electrodes, a device isolation layer vertically overlapping the stack structure and disposed in the pad region of the substrate, a dummy vertical channel portion penetrating the stack structure on the pad region of the substrate and disposed in the device isolation layer, and a dummy semiconductor pillar disposed between the dummy vertical channel portion and one portion of the substrate being in contact with one sidewall of the device isolation layer.

A circuit measuring the operating speed of a semiconductor memory chip in relation to a defined asynchronous access time is disclosed. The circuit includes a test signal path extending between a test input pad and a test output pad and is formed by a plurality of test signal path segments and at least one delay element associated with at least one of the plurality of test signal path segments, such that a delay time for a test signal communicated through the test signal path is indicative of the actual asynchronous access time for the semiconductor memory chip. Each one of the plurality of test signal path segments is either an interior test signal path segment or an exterior test signal path segment.

A multipurpose terminal receives an address signal and a data signal. An address valid terminal receives an address valid signal indicating that a signal supplied to the multipurpose terminal is the address signal. An arbiter determines which of an external access request and an internal refresh request is given priority. The arbiter disables reception of the internal fresh request in response to a fact that both a chip enable signal and the address valid signal reach a valid level (an external access request). The arbiter enables the reception of the internal refresh request in response to completion of read or write operation. As a result, in a semiconductor memory device including the multipurpose terminal which receives the address signal and the data signal, contention between the read operation and the write operation, and a refresh operation which responds to the internal refresh request is prevented, which prevents a malfunction.

A method according to some embodiments of the invention includes forming a first gate pattern on a first region of a semiconductor substrate. The first gate pattern is formed to have a first gate insulating layer pattern, a first lower gate conductive layer pattern and a gate etching stopper layer pattern which are sequentially stacked. A second gate pattern is formed on a second region spaced apart from the first region to define a border region between the first and second regions. The second gate pattern is formed to have a second gate insulating layer pattern and a second lower gate conductive layer pattern, which are sequentially stacked. Thus, some embodiments may prevent two different gate conductive layers from overlapping with each other in the border region. Accordingly, semiconductor memory devices according to some embodiments of the invention do not have undesired active regions formed in the border region.

This disclosure concerns a memory including a memory cell including a floating body in an electrically floating state and storing data according to the number of majority carriers in the floating body; a word line connected to a gate of the memory cell; a first bit line connected to the memory cell to transmit the data; a second bit line transmitting reference data used to detect the data stored in the memory cell; a first sense node and a second sense node transmitting the data stored in the memory cell and the reference data, respectively; a first short-circuiting switch provided between the first sense node and the second sense node; and a first flip-flop applying a load current to the memory cell during a data read operation and amplifying a potential difference generated between the first sense node and the second sense node by turning off the first short-circuiting switch

A spare column on which spare memory cells are arranged is provided in a memory cell array. In the memory cell array, address assignment can be altered so that sub-word lines selected collectively according to the same row address is divided into the right and left halves. The alteration in assignment can be realized by disconnecting a fuse element incorporated in a SD generating circuit. Even in a case where a plurality of defective memory cells are concentrated on the same memory cell row, the number of defective memory cells in a select unit corresponding to row address can be altered by alteration in address assignment so as to be reduced as a result of distribution; thereby enabling increase in number of chips that can be saved with spare memory cells. Accordingly, improvement on saving rate for defective chips can be realized without increasing the number of spare memory cells.

A semiconductor memory device includes an I/O line for transmitting read data that has been read from a memory cell, a plurality of driver circuits for driving the I/O line on the basis of the read data, a read circuit for receiving the read data transmitted through the I/O line, and an assist circuit for amplifying the read data transmitted through the I/O line. The assist circuit is disposed farther away from a prescribed drive circuit included in the plurality of drive circuits as viewed from the read circuit. The signal level can thereby rapidly change levels even in memories having relatively long I/O lines.

According to an aspect of one embodiment, it is provided that semiconductor memory device determining a data read time required to read data from a memory cell by an operation to read a replica cell to which a replica bit line having a load equivalent to a bit line to be connected to the memory cell and a replica word line are connected, the semiconductor memory device comprising: a write control signal generating unit that includes logic gates coupled in multi stages for receiving an input of a replica word line activating signal generated in response to a driving signal for driving the replica word line, the write control signal generating unit generating a write control signal to determine a data write time required to write data in the memory cell based on the replica word line activating signal.

Final sections of the word lines are arranged in a staggered fashion to fan out and have larger lateral extensions than the word lines. Interspaces are filled with a dielectric material, and a mask is applied that partially covers the final sections and leaves contact areas in regions adjacent to the final sections and to the interspaces open. This mask is used to remove the dielectric material between the word line stacks. A second word line layer is applied and planarized to form second word lines between the first word lines, which have contact areas arranged in a staggered fashion to fan out like the final sections of the first word lines.

A buffer circuit of a semiconductor memory apparatus includes a buffering section configured to increase or decrease a voltage level of an output node by comparing a voltage level of an input signal with a voltage level of a reference voltage. A voltage compensation section applies a voltage to the output node in proportion to a variation of the reference voltage when the level of the reference voltage is lower than a target level.

Provided is a semiconductor memory device including: first and second SRAM cells; a first bit line pair provided with the first SRAM cell; a second bit line pair provided with the second SRAM cell; a first switch circuit provided between the first bit line pair and the second bit line pair; and a controller that controls the first switch circuit to render the first bit line pair and the second bit line pair conductive, in a case of testing the first SRAM cell.