摘要:
A semiconductor memory device is provided in which an electrode applied with the power supply voltage or the ground voltage is provided on an insulating layer over the drain and/or the gate of the MOS transistors constituting the memory cell of a static memory device, thereby to increasing the capacitance of the storing node of the memory cell. This semiconductor memory device significantly reduces the occurrence of soft errors.
摘要:
Each of the memory cells in a SRAM includes two driver MOS transistors, two transfer gate MOS transistors and two load resistances. The gate electrode layers of the MOS transistors are formed from a first-level conductive layer provided on the surface of a semiconductor substrate. The source regions of the two driver MOS transistors in each memory cell are connected in common and further connected to a ground potential point through a second-level conductive layer. The two load resistances in each memory cell are formed from a third-level high-resistance material layer. The second-level conductive layer is formed from a low-resistance material layer. Thus the resistance of the sources of the two driver MOS transistors is lowered.
摘要:
A semiconductor static random access memory having a high .alpha.-ray immunity and a high packing density is provided which is also capable of high-speed operation. A semiconductor memory device comprises static random access memory cells each including a flip-flop circuit. Storage nodes of each flip-flop circuit have respective pn-junctions formed at regions sandwiched between gate electrodes of first insulated gate field effect transistors and gate electrodes of second insulated gate field effect transistors, respectively. The pn-junction has an area smaller than that of a channel portion of the first or second insulated gate field effect transistor. The gate electrode of one of the two first insulated gate field effect transistors and the drain region of the other insulated gate field effect transistor, on one hand, and the drain region of the one insulated gate field effect transistor and the gate electrode of the other insulated gate field effect transistor, on the other hand, are electrically cross-coupled mutually through first and second electrically conductive films, respectively. Also, to increase packing density and enhance immunity to soft error, the gate electrodes of the first and second insulated gate field effect transistors extend substantially in parallel with one another and the channel regions of the first and second insulated gate field effect transistors extend substantially in parallel with one another.
摘要:
A static random access memory cell in which capacitors are electrically connected to storage nodes, so that the memory cell will not suffer from soft error even when it is hit by alpha particles. The memory cell has MOS transistors, capacitors constituted by two polycrystalline silicon layers, and resistors constituted by a polycrystalline silicon layer, that are formed on a semiconductor substrate.
摘要:
A resistance element having a reduced occupied area and a high resistance which may be employed as a load resistor used in, for example, a static memory device. A high-resistance area is formed using a relatively thin film, while an interconnection area is formed using a relatively thick film, and these films are provided in such a manner that the thin film is in contact with the upper side of the thick film (the relatively thick film is a first-level film, and the relatively thin film is a second-level film).
摘要:
A memory cell of the type employing a pair of cross-coupled CMOS inverters of a SRAM is disclosed in which the load MISFETs are stacked above the semiconductor substrate and over the drive MISFETs. Each load MISFET of a memory cell consists of a source, drain and channel region formed of a semiconductor strip, such as a polycrystalline silicon film strip, and a gate electrode consisting of a different layer conductive film than that of the drive MISFETs. In a memory cell having such a stacked arrangement, the source region and gate electrode of each load MISFET thereof are patterned to have a widely overlapping relationship with each other to form a capacitor element thereacross such that an increase in the overall capacitance associated with each of the memory cell storage nodes is effected thereby decreasing occurrence of soft error. The overlapping relationship for effecting the large capacitor element across the source and gate of the respective load MISFETs is provided by an ion implanting scheme of a p-type impurity into the semiconductor strip. A separate mask for ion-implantation for the formation of the source region of the load MISFET is added followed by the addition of the gate electrode thereof in a manner so as to have a widely overlapping relationship with that of the source region.
摘要:
A memory cell of the type a pair of cross-coupled CMOS inverters of a SRAM is disclosed in which the load MISFETs are stacked above the semiconductor substrate and over the drive MISFETS. Each load MISFET of a memory cell consists of a source, drain and channel region formed within the same polycrystalline silicon film, and a gate electrode consisting of a different layer conductive film than that of the drive MISFETs. In a memory cell having such a stacked arrangement, the source (drain) region and gate electrode of each load MISFET thereof are patterned to have an overlapping relationship with each other so as to increase the effective capacitance associated with each of the memory cell storage nodes. The gate electrodes of both the drive and load MISFETs are formed of n-type and p-type polycrystalline silicon films, respectively, and the drain regions of the first and second p-channel load MISFETs are electrically connected to the drain regions of the first and second n-channel drive MISFETs through separate polycrystalline silicon films, respectively. The polycrystalline silicon gate electrodes of the first and second load MISFETs are respectively electrically connected to the drain regions of the second and first drive MISFETs in each memory cell of the SRAM, furthermore.
摘要:
A semiconductor memory having static cells each composed of two driver MOS transistors formed on a semiconductor substrate and two transfer MOS transistors and two load resistors, which are formed on the substrate and are connected to the drains of the driver MOS transistors, respectively. A conductive film for fixing the sources of the driver MOS transistors to a ground voltage is formed above the principal surface of the semiconductor substrate, and this conductive film defines one electrode of a capacitance element formed on the substrate. The conductive film is formed over the load resistors formed on the semiconductor substrate so as to constitute an electric field shield for the load resistors.
摘要:
The manufacture of a memory cell of the type employing a pair of cross-coupled CMOS inverters of a SRAM is disclosed in which the load MISFETs are stacked above the semiconductor substrate and over the drive MISFETs. The manufacture of each load MISFET consists of forming source, drain and channel regions within the same polycrystalline silicon film, and a gate electrode consisting of a different layer conductive film, such as a polycrystalline film, than that of the drive MISFETs. The manufacture of the memory cell having such a stacked arrangement, facilitates the patterning of the source (drain) region and gate electrode of each load MISFET thereof to have an overlapping relationship with each other so as to increase the effective capacitance associated with each of the memory cell storage nodes. The gate electrodes of both the drive and load MISFETs are formed of n-type or of n-type and p-type polycrystalline silicon films, respectively, and electrical connections are formed between the drain regions of the first and second p-channel load MISFETs with that of the drain regions of the first and second n-channel drive MISFETs through separate polycrystalline silicon films, respectively. Also, there are formed electrical connections between the polycrystalline silicon gate electrodes of the first and second load MISFETs with that of drain regions of the second and first drive MISFETs, through the poly-Si gate electrodes of the first and second drive MISFETs, in each memory cell of the SRAM, respectively, furthermore.
摘要:
In a memory cell of SRAM of CMOS type, load MISFET having a polycrystalline silicon film as area of source, drain and channel is stacked on drive MISFET, and gate electrodes of the drive MISFET and the load MISFET are constituted by conductive films in different layers. Area of source and drain provided on the polycrystalline silicon film has an overlapped area with the gate electrode of the load MISFET.