Abstract:
On transistors P1, P2, N1 and N2 constituting an NAND gate, interconnection pattern W of metal having high melting point and aluminum interconnection patterns Al1 and Al2 are stacked. A local line LL for connecting transistors P1, P2, N1 and N2 to each other is formed by the interconnection pattern W of metal having high melting point, signal lines SL and SL' for signal input/output between the NAND gate and the outside are formed by aluminum interconnection pattern Al1, and power supply lines VL and VL' for applying power supply potentials Vcc and Vss to the NAND gate are formed by the aluminum interconnection pattern Al2. As compared with the prior art in which the local line LL is formed by the aluminum interconnection pattern Al1, the degree of freedom in layout can be improved and the layout area can be reduced.
Abstract:
A semiconductor memory device of folded bit line structure provided with a cross portion in at least one portion of each of bit line pairs so that values of coupling capacitance with adjacent bit line pairs are equal to each other with respect to the paired bit lines.Preferably, the respective bit line pairs are equally divided into 4N and the cross parts are provided at dividing points so that bit line pairs having the cross parts at the same dividing points are arranged on alternate pairs of bit lines.Preferably, the cross parts are provided in regions for forming restore circuits or sense amplifiers.More preferably, a dummy word line for selecting dummy cells for providing reference potential is selected by the position of a selected word line.
Abstract:
A semiconductor memory device of folded bit line structure provided with a cross portion in at least one portion of each of bit line pairs so that values of coupling capacitance with adjacent bit line pairs are equal to each other with respect to the paired bit lines. Preferably, the respective bit line pairs are equally divided into 4N and the cross parts are provided at dividing points so that bit line pairs having the cross parts at the same dividing points are arranged on alternate pairs of bit lines. Preferably, the cross parts are provided in regions for forming restore circuits or sense amplifiers. More preferably, a dummy word line for selecting dummy cells for providing reference potential is selected by the position of a selected word line.
Abstract:
A MOS dynamic type RAM comprises memory cells (10), dummy cells (11), bit line pairs (BL, BL), word lines (WL), dummy word lines (DWL) and sense amplifiers (12). In a non-active cycle, the potentials of each pair of bit lines (BL, BL) are precharged at 1/2 of a supply potential V.sub.CC. Each sense amplifier (12) operates in an active cycle following the non-active cycle, while each active pull-up circuit (13) pulls up the potential of a higher level one of the pair of bit lines to V.sub.CC. This active cycle is defined by an internal RAS internal signal, which is generated by a NAND circuit (27) in response to an external RAS signal and an RPW signal obtained by delaying the external RAS signal by a delay circuit (20) and having a trailing edge obtained by delaying the trailing edge of the external RAS signal by a prescribed period.
Abstract:
A dynamic RAM comprises an array of memory cells, each of the memory cells comprising a single access transistor and a charge storage region. The charge storage region comprises a first capacitor memory including a P.sup.+ region serving as an opposite electrode formed in the inner surface of a trench formed in a P type silicon substrate, a first capacitor dielectric film formed on the P.sup.+ region and a common electrode layer serving as a memory terminal formed on the first capacitor dielectric film, and a second memory capacitor including the common electrode layer, a second capacitor dielectric film formed on the common electrode layer and a cell plate electrode formed on the second capacitor dielectric film. The memory terminal and a drain region of the access transistor are connected in a self-aligning manner by an electrode having a sidewall shape which is in contact with an end of the memory terminal. Thus, a contact hole need not be formed in the first capacitor dielectric film, so that decrease of the electrical reliability of the first capacitor dielectric film can be prevented. The drain region of the access transistor may be formed by self-alignment with the contact portion of the common electrode layer.
Abstract:
In the semiconductor memory device according to the present invention, a n type drain diffused region (9a) to be connected to a bit line (12) is formed on a p type semiconductor substrate (1) and a n type source diffused region (9b) is formed with a prescribed spacing from the n type drain region (9a). On the p type silicon substrate (1), a p type diffused region (16a) of high impurity density and p type diffused region (16b) of high impurity density are formed in such a manner that they are in contact with the n type drain diffused region (9a) and the n type source diffused region (9b), respectively, but not in the channel region of the n channel MOS transistor (18). Consequently, the .alpha. particle-generated charges can be decreased without changing the threshold voltage of the transfer gate transistor.
Abstract:
A test signal generator for a semiconductor integrated circuit memory, wherein when transfer transistors (20, 21, 14, 15) are rendered conductive, a test data cloumn is supplied from an I/O line pair (11, 12) to a column of a register (10) and stored therein. When a transfer (67) is rendered conductive, the test data column written in the register is written in a column of a memory cell (22) in the same pattern and when transfer transistors (16, 17) are rendered conductive, the test data column written in the register is inverted and the, written in the memory cell column, Data in the memory cell column is read out by a word line (13) and amplified by a sense amplifier (5), so that the data and the test data stored in the register are compared by a coincidence detection circuit 8 to detect whether it is coincident or not.
Abstract:
Each of the bit lines constituting each of a plurality of bit line pairs included in a portion of a memory cell array comprises even-numbered intersecting portions. At the intersecting portion, the materials of respective bit lines are different from each other. The bit lines are formed of the same material at portions other than the intersecting portions. The intersecting portions are arranged such that one of the bit lines constituting each bit line pair neighbors one of the bit lines constituting an adjacent one of the bit line pairs for a first length and neighbors the other one of the bit lines constituting the adjacent bit line pair for a second length; and the other one of the bit lines constituting the bit line pair neighbors the one of the bit lines of the adjacent bit line pair for the first length and neighbors the other one of the bit lines of the adjacent bit line pair for the second length.
Abstract:
There are provided a first memory cell array and a second memory cell array. The first memory cell array comprises a dynamic RAM and the second memory cell array comprises a static RAM. In addition, the second memory cell array has smaller capacity than that of the first memory cell array. An error correcting circuit, a check bit generating circuit and a register are connected between the first memory cell array and the second memory cell array. Data which is frequently accessed is transferred from the first memory cell array to the second memory cell array and stored therein. Access is made to the second memory cell array. When data which is required is not in the second memory cell array, access is made to the first memory cell array. At the time of transferring data from the first memory cell array to the second memory cell array, errors are corrected by the error correcting circuit. The check bit generating circuit is responsive to data whose error is corrected by the error correcting circuit for generating new check bits.
Abstract:
A semiconductor memory device comprises a plurality of memory cell array blocks. An address changing system is provided in each memory cell array block. The same address signal is applied to these address changing systems. Each address changing system comprises a plurality of linking devices. By previously blowing out any of the linking devices in each address changing system, an externally applied address signal is changed with another address signal to be applied to a corresponding memory cell array block.