Abstract: Numerous examples are disclosed for verifying a weight programmed into a selected non-volatile memory cell in a neural memory. In one example, a circuit comprises a digital-to-analog converter to convert a target weight comprising digital bits into a target voltage, a current-to-voltage converter to convert an output current from the selected non-volatile memory cell during a verify operation into an output voltage, and a comparator to compare the output voltage to the target voltage during a verify operation.

Abstract: A method includes recessing an upper surface of a substrate in first and second areas relative to a third area, forming a first conductive layer in the first area, forming a second conductive layer in the three areas, selectively removing the first and second conductive layers in the first area, while maintaining the second conductive layer in the second and third areas, leaving pairs of stack structures in the first area respectively having a control gate of the second conductive layer and a floating gate of the first conductive layer, forming a third conductive layer in the three areas, recessing the upper surface of the third conductive layer below tops of the stack structures and removing the third conductive layer from the second and third areas, removing the second conductive layer from the second and third areas, and forming blocks of metal material in the second and third areas.

Abstract: In one example, a non-volatile memory system, comprises an array of non-volatile memory cells arranged in rows and columns, each non-volatile memory cell comprising a source and a drain; a plurality of bit lines, each of the plurality of bit lines coupled to the drain or each non-volatile memory cell in a column of non-volatile memory cells; a source line coupled to the source of each non-volatile memory cell; and an adaptive bias decoder for providing a voltage to an erase gate line of the array during an operation, wherein the adaptive bias decoder adjusts the voltage provided to the erase gate line in response to changes in a voltage of the source line.

Abstract: In one example, a system comprises an analog neural memory array comprising a plurality of non-volatile memory cells arranged into rows and columns; and a voltage generator to provide a voltage to one or more rows of the analog neural memory array, the voltage generator comprising a voltage ladder to generate a plurality of voltages according to a logarithmic formula.

Abstract: In one example, a method comprises applying a first programming pulse to a terminal of a selected non-volatile memory cell; and applying a second programming pulse to the terminal of the selected non-volatile memory cell, wherein a magnitude of a voltage the second programming pulse is equal to or lower than a magnitude of a voltage of the first programming pulse; wherein the selected non-volatile memory cell is programmed to a target value by the first programming pulse and the second programming pulse.

Abstract: In one example, a non-volatile memory system, comprises an array of non-volatile memory cells arranged in rows and columns, each non-volatile memory cell comprising a source and a drain; a plurality of bit lines, each of the plurality of bit lines coupled to the drain or each non-volatile memory cell in a column of non-volatile memory cells; a source line coupled to the source of each non-volatile memory cell; and an adaptive bias decoder for providing a voltage to the source line of the array during operation.

Abstract: In one example, a non-volatile memory system comprises an array of non-volatile memory cells arranged in rows and columns, each non-volatile memory cell comprising a source and a drain; a plurality of bit lines, each of the plurality of bit lines coupled to the drain of each non-volatile memory cell in a column of non-volatile memory cells; a source line coupled to the source of each non-volatile memory cell; and an adaptive bias decoder for providing a voltage to a word line of the array during an operation, wherein the adaptive bias decoder adjusts the voltage provided to the word line in response to changes in a voltage of the source line.

Abstract: In one example, a circuit comprises an input transistor comprising a first terminal, a second terminal coupled to ground, and a gate; a capacitor comprising a first terminal and a second terminal; an output transistor comprising a first terminal providing an output current, a second terminal coupled to ground, and a gate; a first switch; and a second switch; wherein in a first mode, the first switch is closed and couples an input current to the first terminal of the input transistor and the gate of the input transistor and the second switch is closed and couples the first terminal of the input transistor to the first terminal of the capacitor and the gate of the output transistor, and in a second mode, the first switch is open and the second switch is open and the capacitor discharges into the gate of the output transistor.

Abstract: In one example, a system comprises a neural network array of non-volatile memory cells arranged in rows and columns; and a logical cell comprising a first plurality of non-volatile memory cells in a first row of the array and a second plurality of non-volatile memory cells in a second row adjacent to the first row; wherein the first plurality of non-volatile memory cells and the second plurality of non-volatile memory cells are configured as one or more coarse cells and one or more fine cells.

Abstract: Numerous examples for performing tuning of a page or a word of non-volatile memory cells in an analog neural memory are disclosed. In one example, an analog neural memory system comprises an array of non-volatile memory cells arranged into rows and columns, each non-volatile memory cell comprising a word line terminal, a bit line terminal, and an erase gate terminal; a plurality of word lines, each word line coupled to word line terminals of a row of non-volatile memory cells; a plurality of bit lines, each bit line coupled to bit line terminals of a column of non-volatile memory cells; and a plurality of erase gate enable transistors, each erase gate enable transistor coupled to erase gate terminals of a word of non-volatile memory cells.

Abstract: Numerous embodiments of analog neural memory arrays are disclosed. Certain embodiments comprise an adaptive bias decoder for providing additional bias to array input lines to compensate for instances where ground floats above 0V. This is useful, for example, to minimize the voltage drop for a read, program, or erase operation while maintaining accuracy in the operation.

Abstract: An artificial neural network device that utilizes one or more non-volatile memory arrays as the synapses. The synapses are configured to receive inputs and to generate therefrom outputs. Neurons are configured to receive the outputs. The synapses include a plurality of memory cells, wherein each of the memory cells includes spaced apart source and drain regions formed in a semiconductor substrate with a channel region extending there between, a floating gate disposed over and insulated from a first portion of the channel region and a non-floating gate disposed over and insulated from a second portion of the channel region. Each of the plurality of memory cells is configured to store a weight value corresponding to a number of electrons on the floating gate. The plurality of memory cells are configured to multiply the inputs by the stored weight values to generate the outputs. Various algorithms for tuning the memory cells to contain the correct weight values are disclosed.

Abstract: A memory device with memory cell pairs each having a single continuous channel region, first and second floating gates over first and second portions of the channel region, an erase gate over a third portion of the channel region between the first and second channel region portions, and first and second control gates over the first and second floating gates. For each of the pairs of memory cells, the first region is electrically connected to the second region of an adjacent pair of memory cells in the same active region, and the second region is electrically connected to the first region of an adjacent pair of the memory cells in the same active region.

Abstract: Numerous embodiments are disclosed for compensating for differences in the slope of the current-voltage characteristic curve among reference transistors, reference memory cells, and flash memory cells during a read operation in an analog neural memory in a deep learning artificial neural network. In one embodiment, a method comprises receiving an input voltage, multiplying the input voltage by a coefficient to generate an output voltage, applying the output voltage to a gate of a selected memory cell, performing a sense operating using the selected memory cell and a reference device to determine a value stored in the selected memory cell, wherein a slope of a current-voltage characteristic curve of the reference device and a slope of the current-voltage characteristic curve of the selected memory cell are approximately equal during the sense operation.

Abstract: Numerous examples of a precision programming apparatus are disclosed for precisely and quickly depositing the correct amount of charge on the floating gate of a non-volatile memory cell within a vector-by-matrix multiplication (VMM) array in an artificial neural network. In one example, a neuron output circuit for providing a current to program as a weight value in a selected memory cell in a vector-by-matrix multiplication array is disclosed, the neuron output circuit comprising a first adjustable current source to generate a scaled current in response to a neuron current to implement a positive weight, and a second adjustable current source to generate a scaled current in response to a neuron current to implement a negative weight.

Abstract: Numerous embodiments are disclosed for verifying a weight programmed into a selected non-volatile memory cell in a neural memory. In one embodiment, a circuit for verifying a weight programmed into a selected non-volatile memory cell in a neural memory comprises a converter for converting a target weight into a target current and a comparator for comparing the target current to an output current from the selected non-volatile memory cell during a verify operation. In another embodiment, a circuit for verifying a weight programmed into a selected non-volatile memory cell in a neural memory comprises a digital-to-analog converter for converting a target weight comprising digital bits into a target voltage, a current-to-voltage converter for converting an output current from the selected non-volatile memory cell during a verify operation into an output voltage, and a comparator for comparing the output voltage to the target voltage during a verify operation.

Abstract: In one example, a method comprises performing a first programming process on a selected non-volatile memory cell, the first programming process comprising a plurality of program-verify cycles, wherein a programming voltage duration of increasing period is applied to one of a floating gate, a control gate terminal, an erase gate terminal, and a source line terminal of the selected non-volatile memory cell in each program-verify cycle after the first program-verify cycle.

Abstract: A method of forming a memory device that includes forming a first insulation layer, a first conductive layer, and a second insulation layer on a semiconductor substrate, forming a trench in the second insulation layer to expose the upper surface of the first conductive layer, performing an oxidation process and a sloped etch process to reshape the upper surface to a concave shape, forming a third insulation layer on the reshaped upper surface, forming a conductive spacer on the third insulation layer, removing portions of the first conductive layer leaving a floating gate under the conductive spacer with the reshaped upper surface terminating at a side surface at a sharp edge, and forming a word line gate laterally adjacent to and insulated from the floating gate. The conductive spacer includes a lower surface that faces and matches the shape of the reshaped upper surface.

Abstract: Numerous examples for performing tuning of a page or a word of non-volatile memory cells in an analog neural memory are disclosed. In one example, a method comprises programming a word or page of non-volatile memory cells in an analog neural memory system; and identifying any fast bits in the word or page of non-volatile memory cells.

Abstract: Numerous embodiments are disclosed for compensating for differences in the slope of the current-voltage characteristic curve among reference transistors, reference memory cells, and flash memory cells during a read operation in an analog neural memory in a deep learning artificial neural network. In one embodiment, a method comprises receiving a first voltage, multiplying the first voltage by a coefficient to generate a second voltage, applying the first voltage to a gate of one of a reference transistor and a selected memory cell, applying the second voltage to a gate of the other of a reference transistor and a selected memory cell, and using the reference transistor in a sense operation to determine a value stored in the selected memory cell.