摘要:
An improved contactless EPROM array, EPROM cell design, and method for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is-coupled through a top block select transistor to global bitline. The cell structure uses two metal global bitlines which extend essentially parallel to the drain, source and drain diffusion regions, and a virtual ground conductor which couples a plurality of columns of transistors to a virtual ground terminal through a horizontal conductor, such as a buried diffusion line.
摘要:
An improved contactless EPROM array, EPROM cell design, and method for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is coupled through a top block select transistor to global bitline. The cell structure uses two metal global bitlines which extend essentially parallel to the drain, source and drain diffusion regions, and a virtual ground conductor which couples a plurality of columns of transistors to a virtual ground terminal through a horizontal conductor, such as a buried diffusion line.
摘要:
A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.
摘要:
A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.
摘要:
An improved contactless EPROM array, EPROM cell design, and method for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is coupled through a top block select transistor to global bitline. The cell structure uses two metal global bitlines which extend essentially parallel to the drain, source and drain diffusion regions, and a virtual ground conductor which couples a plurality of columns of transistors to a virtual ground terminal through a horizontal conductor, such as a buried diffusion line.
摘要:
Novel contactless FLASH EPROM cell and array designs, and methods for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is coupled through a top block select transistor to global bitline. The cell structure uses two metal global bitlines which extend essentially parallel to the drain, source and drain diffusion regions, and a virtual ground conductor which couples a plurality of columns of transistors to a virtual ground terminal through a horizontal conductor, such as a buried diffusion line.
摘要:
An integrated circuit comprises a functional module such as a FLASH memory with automatic program and erase circuits, test circuitry coupled with the functional module which executes a test of the functional module and generates status information as a result of the test, and non-volatile status write circuitry coupled with the test circuitry on the chip. A circuit in the non-volatile status write circuitry is responsive to the test of the functional circuitry to write the status information to the non-volatile memory. A port is provided on the integrated circuit coupled to the non-volatile memory through which the status information stored in the non-volatile memory is accessible in a test read mode to external devices. In a FLASH EPROM embodiment, the IC includes an array of FLASH EPROM memory cells and a port through which data in the array is accessible by external devices. A test set of FLASH EPROM memory cells is provided in the array. Program and erase circuitry, coupled to the array, has a test mode to exercise the program and erase circuitry to generate status information indicating results of the test and test read mode to read out the status information. Non-volatile status write circuitry, is coupled to the program and erase circuitry and the test set, and writes the status information to the test set. The program and erase circuits include retry counts with programmable thresholds for reducing the test times of the devices.
摘要:
A flexible technique for improving yield of manufacturing of high density of memory devices, such as flash EEPROM, involves reconfiguring an integrated circuit memory array having a plurality of sectors selected by an address decoder in response to an N bit field in an address. If defective sectors are detected in the array, it is partitioned to disable defective sectors by configuring a sector decoder to prevent access to the defective sectors while maintaining sequential addressing remaining sectors in the array. The step of partitioning includes configuring the sector decoder to replace a defective sector in one half of the array by another sector in the other half of the array having N-m of the N address bits in common with the defective sector when m is between 1 and N-1.
摘要:
A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.
摘要:
A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.