Macronix International Co., Ltd.

Skymedi Corporation

I-Long Lee

Ray-Lin Wan

Kuen-Long Chang

Chun-Hsiung Hung

Tzeng-Huei Shiau

Tien-Shin Ho

Ken-Hui Chen

Yi-Ching Liu

Chun Hsiung Hung

Tom D Yiu

Fuchia Shone

Fuja Shone

Han-Sung Chen

Teruhiko Kamei

Ming-Hung Chou

Ray L Wan

Chia-Shing Chen

Yao-Wu Cheng

Yin-Shang Liu

Jin-Lien Lin

Hsin-Chien Chen

Wen-Lin Chang

Yuan-Chang Liu

Kouta Soejima

Tzeng-Hei Shiau

Hun-Song Chen

A programming method for programming stored bits in floating gates of a flash memory cell or selected flash memory cells of a flash memory array is utilized for applying SSI injection on said flash memory cell or said selected flash memory cells of a flash memory array is disclosed. Constant charges at the drain regions of said flash memory cell or said selected flash memory cells of the flash memory array is implemented with a capacitor and a related switch for suppressing variant injected-charges-related properties in applying the SSI injection. A constant biasing current, which may be implemented with a constant current source or a current mirror equipped with a constant current source, is applied on source regions of said flash memory cell or said selected flash memory cells of the flash memory array for enhancing the suppression of said variant biasing properties.

Method of programming a nonvolatile memory cell and related memory array

A method for programming a split gate memory cell comprises the following steps. First, a split gate memory cell formed on a semiconductor substrate of a first conductive type, e.g., p-type, is provided. The split gate memory cell has two bitlines of a second conductive type, e.g., n-type, a select gate, a floating gate, a wordline and a dielectric layer deposited between the floating gate and the semiconductor substrate, wherein the select gate and floating gate are transversely disposed between the two bitlines, the wordline is above the select gate and floating gate. Second, a positive voltage is applied to the wordline so as to turn on the floating gate, and a negative voltage is applied to the bitline next to the floating gate, whereby a bias voltage across the tunnel dielectric layer is generated for programming, that is, the so called F-N programming.

Programming and manufacturing method for split gate memory cell

An output driver for an integrated circuit performs a precharge function before internal data is available, minimizing the access time for such data. Also, the pull up and pull down circuitry used in the precharge function is separate from the output driver, and independent of the level of the data signal to be driven. A sense circuit senses an initial state of the output pad, before the output signal is supplied to the output pad, which indicates whether a voltage level on the output pad is above a threshold or below the threshold. A precharge circuit includes a pull up circuit and a pull down circuit. The pull up circuit is responsive to the initial state indicating that the voltage level on the output is below the threshold, and the pull down circuit is responsive to the initial state indicating that the voltage level on the output is above the threshold. A detector is coupled to the output, and produces a control signal indicating when output is near the threshold. Logic is responsive to the control signal from the detector to turn off the precharge circuit when the threshold is reached.

Output pad precharge circuit for semiconductor devices

An on chip voltage generation circuit is provided suitable for use on integrated circuits such as flash memory devices with a low power supply voltage (e.g., 2.7 to 3.6 volts). A voltage boost circuit is coupled to the supply voltage input and to a boost signal, which boosts the on-chip voltage at a node on the integrated circuit in response to a transition of the boost signal. The voltage boost circuit has a first mode which in response to the transition boosts the on-chip voltage at a first rate of boosting until a first threshold, and a second mode which in response to the transition boosts the on-chip voltage at a second rate of boosting until a second threshold. The second rate of boosting in the preferred system is slower than the first rate of boosting. A detection circuit is coupled to the node on the integrated circuit which receives the on-chip voltage, and to the voltage boost circuit. The detection circuit signals the voltage boost circuit when the node reaches the first threshold, and signals the voltage boost circuit when the node reaches the second threshold. According to one aspect of the invention, the first threshold is reached within less than 5 nanoseconds, and more preferably about 2 nanoseconds, or less, of the transition in the boost signal.

Rapid on chip voltage generation for low power integrated circuits

A sensing circuit for sensing the logic state of a memory cell which minimizes read times is described which includes a first circuit branch corresponding to an array circuit path and a second circuit branch corresponding to a reference cell circuit path. In operation during the pre-decode interval, additional load and current generation circuitry are enabled in the first circuit path so that the voltage as seen by the sensing input of a sensing circuit comparator is driven to be essentially equivalent to that of the reference signal as established by the reference cell circuit path on the reference input of the sensing circuit comparator. Once the address has been decoded, the additional load circuitry is disabled so as to allow the sensing input of the comparator to transition to a voltage representative of the logic state stored in the memory cell.

Memory cell sense amplifier

Enhanced word line driver to reduce gate capacitance for low voltage

Series capacitor charge pump with dynamic biasing

In a floating gate memory that has a buffer that can be coupled to a set of floating gate memory cells in the memory, a method of writing to a selected portion of the set of floating gate cells. For example, a method of writing a byte to a floating gate memory where the memory uses a page buffer reads and writes to an entire row of cells at a time. Store contents of the set of floating gate cells into the buffer, store the data into a portion of the buffer corresponding to the selected portion of the set of floating gate cells, and store contents of the buffer into the set of floating gate cells. An improved floating gate memory is disclosed in which data may be loaded into a portion of the floating gate cells in a set of cells that may be coupled to a buffer.

Byte-wide write scheme for a page flash device

A new flash memory cell structure and operational bias is based on the use of a triple well flash memory cell which allows pre-programming by Fowler Nordheim (F-N) tunneling over blocks of cells at a time. The floating gate memory cell is made in a semiconductor substrate having a first conductivity type, such as p-type. A first well within the substrate by having a second conductivity type different than the first conductivity type is included. A second well within the first well is also included having the first conductivity type. A drain and a source are formed in the second well having the second conductivity type, and spaced away from one another to define a channel area between the drain and the source. A floating gate and control gate structure is included over the channel area. The floating gate memory cell is coupled with circuits that induce F-N tunneling of electrons out of the floating gate into the channel area of the substrate for erasing by applying a positive voltage to the second well, such as a voltage higher than the supply voltage, applying a positive voltage to the first well, which is substantially equal to the positive voltage of the second well, applying a negative voltage to the control gate of the cell, while the substrate is grounded. A block wide pre-program operation involves F-N tunneling of electrons into the floating gate from the channel area, using a negative voltage in the second well.

Fowler-Nordheim (F-N) tunneling for pre-programming in a floating gate

A circuit is provided for supplying a negative erasing voltage onto the wordlines of selected blocks in an array of floating gate memory cells. The circuit includes a voltage circuit, which has a plurality of local outputs, each of which connects to wordlines of an associated block of floating gate memory cells. A block selector circuit is coupled to the local outputs of the voltage circuit and selectively switches each of the local outputs to apply either an erasing voltage or a non-erasing voltage onto the wordlines of the associated block of floating gate memory cells. Negative wordline stress is thus reduced for wordlines of unselected blocks which receive a less negative, non-erasing voltage during block erase operations.

Block-level wordline enablement to reduce negative wordline stress

Method and system for soft programming algorithm

Growing community of inventors

Hsinchu, Taiwan

I-Long Lee