Abstract: A semiconductor memory in which arbitrary operation mode information is set in a plurality of CRs at test time and by which a test cost is reduced and a method for testing such a semiconductor memory. The plurality of CRs hold operation mode information. When a CR control circuit detects write commands to write to an address for register access or read commands to read from the address for register access in a predetermined order, the CR control circuit updates the operation mode information for each of the plurality of CRs on a time division basis. A command generation section generates the write commands, the read commands, or a test start command by which write operation or read operation does not occur, in response to a control signal from the outside. In addition, the command generation section regenerates the test start command each time the plurality of CRs are updated.

Abstract: A capacitor includes a plurality of laminated thin layers, has a structure in which a lower electrode layer, a dielectric layer and an upper electrode layer are laminated in sequence, a main material of the lower electrode layer is TiN or ZrN, the lower electrode layer contains oxygen, and concentration of the oxygen contained in the lower electrode layer is less than 21 at %.

Abstract: Provided is a capacitor that realizes a capacitance insulation film having a large relative permittivity and has sufficient capacitance even if an occupied space is small with a reduced amount of leakage current. A capacitor includes: a capacitance insulation film; and an upper electrode and lower electrode each formed on both sides of the capacitance insulation film. The capacitance insulation film is a complex oxide whose main ingredients are Zr, Al and O with the composition ratio of Zr to Al being set at (1?x): x (0.01?x?0.15) and is composed of a dielectric substance having a crystal structure. The lower electrode is composed of a conductor whose surface contiguous to at least the dielectric film has an amorphous structure.

Abstract: A semiconductor device includes a word line drive circuit for resetting the word line by driving the word line connected to a memory cell and is constituted so as to switch a reset level of the word line drive circuit, which is set at the time of the reset operation of the word line, between a first potential such as a ground potential and a second potential such as a negative potential. Further, a semiconductor device including a memory cell array formed by arranging a plurality of memory cells and a word line reset level generating circuit for generating a negative potential makes it possible to vary the amount of a current supply of the word line reset level generating circuit when non-selected word lines are set to a negative potential by applying the output of the word line reset level generating circuit to the non-selected word lines, and varies the amount of the current supply of the negative potential in accordance with the operation of the memory cell array.

Abstract: A semiconductor device includes a word line drive circuit for resetting the word line by driving the word line connected to a memory cell and is constituted so as to switch a reset level of the word line drive circuit, which is set at the time of the reset operation of the word line, between a first potential such as a ground potential and a second potential such as a negative potential. Further, a semiconductor device including a memory cell array formed by arranging a plurality of memory cells and a word line reset level generating circuit for generating a negative potential makes it possible to vary the amount of a current supply of the word line reset level generating circuit when non-selected word lines are set to a negative potential by applying the output of the word line reset level generating circuit to the non-selected word lines, and varies the amount of the current supply of the negative potential in accordance with the operation of the memory cell array.

Abstract: There is provided a semiconductor device including: a temperature sensor detecting temperature; an inner circuit operating when supplied with a power supply voltage from a power supply line; a switch connected between the power supply line and the inner circuit; and a control circuit performing control in which, in a case where the temperature detected by the temperature sensor is higher than a threshold value, the switch is turned on when the inner circuit is in operation and the switch is turned off when the inner circuit is in non-operation, and in a case where the temperature detected by the temperature sensor is lower than the threshold value, the switch is turned on when the inner circuit is in operation and in non-operation.

Abstract: A semiconductor device, including a word line driver for driving a word line connected to a memory cell in a memory cell array and for resetting the word line when the memory cell changes from an activated to a standby state. The reset level of the word line driver is set when resetting of the word line is performed, and may be switched between first and second potentials. A word line reset level generating circuit varies the amount of negative potential current supply in accordance with memory cell array operating conditions. The semiconductor device includes a plurality of power source circuits, each having an oscillation circuit and a capacitor, for driving the capacitor via an oscillation signal outputted by the oscillation circuit. At least some power source circuits share a common oscillation circuit, and different capacitors are driven via the common oscillation signal.

Abstract: Each program circuit outputs an operating specification signal indicating a first or second operating specification according to a program state. Each specification changing circuit is set by a corresponding block selection signal and outputs an operating specification signal indicating a second operating specification. Each timing control circuit changes an output timing of a precharge control signal for a bit line according to the operating specification signal. By the operating specification signal from the specification changing circuit, a failure can be detected in each memory block before programming a program circuit. Thereafter, the failure can be relieved by the program circuit. The output timing of the precharge control signal can be set for each memory block by a block selection signal without wiring a dedicated signal line for setting each specification changing circuit. Accordingly, increase in chip size can be minimized.

Abstract: An address switch circuit receives a row address signal supplied to a first address terminal group and a column address signal supplied to a second address terminal group. Further, the address switch circuit receives the row address signal supplied to the second address terminal group and thereafter receives the column address signal supplied to the second address terminal group and supplies the received row address signal and the received column address signal to the row decoder and the column decoder during a second operation mode. The number of semiconductor memories that are tested at once can be increased by executing an operation test of the semiconductor memories in the second operation mode. In addition, it becomes possible to test a semiconductor memory using test assets for other semiconductor memories. Consequently, the test efficiency can be improved, and the test cost can be reduced.

Abstract: Each sub word line is coupled to a gate of a transfer transistor of a memory cell. A first switch of a sub word decoder couples the sub word line to a high level voltage line when a main word line is in an activation level. A second switch couples the sub word line to a low level voltage line when the main word line is in an inactivation level. A third switch couples the sub word line to the low level voltage line when a word reset signal line is in an activation level. A reset control circuit disables the inactivation of the main word line or the activation of the word reset signal line during a test mode. One of the second and third switches is forcibly turned off, and thereby, an operation failure of a sub word decoder can be detected easily.

Abstract: A memory device is provided which has: a memory cell to store data; a word line to select the memory cell; a bit line connectable to the selected memory cell; a precharge power supply to supply a precharge voltage to the bit line; a precharge circuit to connect or disconnect the precharge power supply to or from the bit line; and a current limiting element to control the magnitude of a current flowing between the precharge power supply and the bit line at least by two steps according to an operation status.

Abstract: A semiconductor memory and a refresh cycle control method that reduce a standby current by properly changing a refresh cycle according to the temperature of the semiconductor memory. A temperature detection section detects the temperature of the semiconductor memory. A cycle change control section sends a cycle change signal for changing a refresh cycle when the temperature of the semiconductor memory reaches a predetermined cycle change temperature. A refresh timing signal generation section generates a refresh timing signal and changes the cycle of the refresh timing signal in response to the cycle change signal. A constant current generation circuit generates an electric current for generating the refresh timing signal. A low-temperature constant current setting circuit designates the level of the electric current generated in the case that the temperature of the semiconductor memory is lower than or equal to the cycle change temperature.

Abstract: Each program circuit outputs an operating specification signal indicating a first or second operating specification according to a program state. Each specification changing circuit is set by a corresponding block selection signal and outputs an operating specification signal indicating a second operating specification. Each timing control circuit changes an output timing of a precharge control signal for a bit line according to the operating specification signal. By the operating specification signal from the specification changing circuit, a failure can be detected in each memory block before programming a program circuit. Thereafter, the failure can be relieved by the program circuit. The output timing of the precharge control signal can be set for each memory block by a block selection signal without wiring a dedicated signal line for setting each specification changing circuit. Accordingly, increase in chip size can be minimized.

Abstract: An address switch circuit receives a row address signal supplied to a first address terminal group and a column address signal supplied to a second address terminal group. Further, the address switch circuit receives the row address signal supplied to the second address terminal group and thereafter receives the column address signal supplied to the second address terminal group and supplies the received row address signal and the received column address signal to the row decoder and the column decoder during a second operation mode. The number of semiconductor memories that are tested at once can be increased by executing an operation test of the semiconductor memories in the second operation mode. In addition, it becomes possible to test a semiconductor memory using test assets for other semiconductor memories. Consequently, the test efficiency can be improved, and the test cost can be reduced.

Abstract: Each sub word line is coupled to a gate of a transfer transistor of a memory cell. A first switch of a sub word decoder couples the sub word line to a high level voltage line when a main word line is in an activation level. A second switch couples the sub word line to a low level voltage line when the main word line is in an inactivation level. A third switch couples the sub word line to the low level voltage line when a word reset signal line is in an activation level. A reset control circuit disables the inactivation of the main word line or the activation of the word reset signal line during a test mode. One of the second and third switches is forcibly turned off, and thereby, an operation failure of a sub word decoder can be detected easily.

Abstract: A memory device is provided which has: a memory cell to store data; a word line to select the memory cell; a bit line connectable to the selected memory cell; a precharge power supply to supply a precharge voltage to the bit line; a precharge circuit to connect or disconnect the precharge power supply to or from the bit line; and a current limiting element to control the magnitude of a current flowing between the precharge power supply and the bit line at least by two steps according to an operation status.

Abstract: A memory device is provided which has: a memory cell to store data; a word line to select the memory cell; a bit line connectable to the selected memory cell; a precharge power supply to supply a precharge voltage to the bit line; a precharge circuit to connect or disconnect the precharge power supply to or from the bit line; and a current limiting element to control the magnitude of a current flowing between the precharge power supply and the bit line at least by two steps according to an operation status.

Abstract: After a refresh operation, a word control circuit holds the selection state of a word line selection signal line selected in each memory block corresponding to a refresh address. Further, in response to an access request, the word control circuit unselects only a word line selection signal line of a memory block selected by an external address corresponding to this access request. In each memory block, the word line selection signal line once selected is not unselected until the access request is received, so that the frequency of unselection and selection of the word line selection signal lines can be lowered. Consequently, a charge/discharge current of the word line selection signal lines can be reduced, which can reduce current consumption of a semiconductor memory.

Abstract: In order to give all memory blocks the same structure, a redundancy word line and a redundancy bit line are formed in each memory block. A redundancy column selection line is wired in common to the memory blocks. Column redundancy circuits are formed to correspond to respective memory groups each of which consists of a prescribed number of memory blocks, and become effective according to enable signals. A column redundancy selection circuit activates an enable signal according to a block address signal when all row hit signals are deactivated. When one of the row hit signals is activated, the column redundancy selection circuit activates the enable signal corresponding to the activated row hit signal. Since the column redundancy circuit for an arbitrary memory group can be made effective according to the row hit signals, failure relief efficiency can be increased without deteriorating the electric characteristic during an access operation.

Abstract: An equalizing circuit connects a pair of bit lines to each other in response to the activation of an equalizing control signal and connects the pair of bit lines to a precharge voltage line. An equalizing control circuit deactivates the equalizing control signal in response to the activation of a first timing signal. A word line driving circuit activates one of word lines in response to the activation of a second timing signal. A first signal generating circuit of a timing control circuit generates the first timing signal. A second signal generating circuit of the timing control circuit activates the second timing signal after the deactivation of the equalizing control signal accompanying the activation of the first timing signal. A delay control circuit of the second signal generating circuit delays an activation timing of the second timing signal in a test mode from that in a normal mode.