Mostek Corporation

Other

Vernon G McKenny

Tsiu Chiu Chan

David L Taylor

Harold Wallace Dozier

Robert S Green

William M Gosney, Jr

John K Hampton

A fuse protection circuit for an electrically programmable read only memory circuit consists of a fusing element such as an antifuse connected between a bitline and the drain of the access transistor, and which is susceptible to inadvertent activation due to programming voltages applied to the bitline when the access transistor is not being addressed. The fusing element is protected from such inadvertent activation by the addition of a capacitor between the drain of the access transistor and the bitline.

Fuse protection circuit

A field effect transistor storage device for use in programmable read-only memories of the type employing a floating gate and a control gate overlying and aligned with the floating gate. An erase gate is provided adjacent at least one edge of the floating gate for removing charge stored on the floating gate. A method of electrically erasing the storage device includes holding the control gate at a fixed potential to thereby hold the floating gate at a substantially fixed potential while a relatively low voltage is applied to the erase gate to remove charge stored on the floating gate.

Three layer floating gate memory transistor with erase gate over field

A programmable read only memory (PROM) integrated circuit is constructed with two new operating modes: a bit-check mode and a deprogramming mode. In the bit-check mode, circuitry is provided to readily determine the apparent threshold voltage of each programmable transistor within the PROM. In the deprogrammable mode, circuitry is provided to simultaneously subject all programmable transistors within the PROM to a deprogramming stress. The bit-check mode provides a rapid programming method, and the bit-check mode and deprogramming mode are utilized in conjunction with each other to provide a rapid and thorough testing method.

Programmable read only memory integrated circuit with bit-check and

A MOSFET random access memory having an extremely low current load memory cell is disclosed. The memory cell comprises a cross-coupled binary stage in which one or more paths to ground can be selectively switched on or off through true and complement data nodes. Impedance means connect a power supply node to the data nodes for charging the data nodes to predetermined voltage levels. The impedance means comprise an intrinsic-extrinsic junction of a substantially pure, intrinsic semiconductor material and a diffusion of extrinsic conductivity impurities disposed within a region of the intrinsic semiconductor material. The impedance means is formed by an isoplanar silicon gate process as an integral portion of a polycrystalline silicon strip which interconnects the power supply node to a data node. A portion of the polycrystalline silicon strip is extended from the data node to form the gate of the transistor to which it is cross-coupled.

Method of making an extremely low current load device for integrated

Block redundancy is utilized to improve yield and lower die cost for an electrically programmable read only memory (EPROM). The EPROM is organized 8Kx8 with four primary memory blocks on each side of a central row decoder. Each block includes an array of memory cells, column select, column decode, sense amp, data buffer and other overhead circuitry. One block of redundant circuitry is also provided for each set of four blocks and includes a redundant memory matrix, a redundant column decoder, a redundant column select, a redundant sense amp and a redundant data buffer. Incorporated within each primary memory block is a multiplex logic circuit which is independently programmable to selectively disconnect the associated primary memory block and substitute the redundant memory block, including the redundant column decoder, column select, sense amp and data buffer. Each multiplex logic circuit includes a polysilicon fuse which is permanently programmable from a closed to an open circuit condition by applying a high voltage to the external data bit terminal which corresponds with the defective memory block cells. According to this arrangement, for each group of blocks, one out of four primary memory arrays including the associated column select, column decoder, sense amp and data buffer, may be replaced during wafer testing and after encapsulation.

Block redundancy for memory array

Extremely low current load device for integrated circuit

The invention disclosed herein is a high performance inverter circuit using MOSFETs having varying threshold voltages produced by selectively varying ion implantation doses in the channels of the MOSFETs and using a slightly depletion type MOSFET, rather than a conventional depletion type, in the output stage.

High performance inverter circuits

A symmetrical structural layout for the principal components of each cell in a group of four mutually contiguous cells of an array of memory cells is disclosed. A common drain supply node is centrally disposed within the group and is coincident with the intersection of first and second mutually perpendicular axes of symmetry. Corresponding components of contiguous cells in each row and column are symmetrically disposed with respect to each of the first and second axes of symmetry. In a preferred embodiment, the principal components of each cell include a plurality of insulated gate field-effect transistors each having a source diffusion region and a drain diffusion region formed within the substrate and a plurality of impedance devices electrically connecting the common drain supply node to the drain diffusions of the transistors in each cell. The impedance devices extend radially from the common drain supply node into the interior of each cell, and at least one of the diffused regions of each transistor in each cell is formed in common with a diffused region of a transistor of a contiguous cell.

Growing community of inventors

Carrollton, TX, United States of America

Vernon G McKenny