Abstract: A method of fabricating an oxide-nitride-oxide (ONO) layer in a memory cell to retain charge well in the nitride layer includes the steps of forming a bottom oxide layer on a substrate, depositing a nitride layer and oxidizing a top oxide layer, thereby causing oxygen to be introduced into the nitride layer. Another method includes the steps of forming a bottom oxide layer on a substrate, depositing a nitride layer and oxidizing a portion of a top oxide layer, thereby causing oxygen to be introduced into the nitride layer and depositing a remaining portion of the top oxide layer, thereby assisting in controlling the amount of oxygen introduced into the nitride layer. A farther method includes the steps of forming a bottom oxide layer on a substrate, depositing a nitride layer, depositing a portion of a top oxide layer and oxidizing a remaining portion of the top oxide layer, thereby causing oxygen to be introduced into the nitride layer.

Abstract: A non-volatile electrically erasable programmable read only memory (EEPROM) capable of storing two bit of information having a nonconducting charge trapping dielectric, such as silicon nitride, sandwiched between two silicon dioxide layers acting as electrical insulators is disclosed. The invention includes a method of programming, reading and erasing the two bit EEPROM device. The nonconducting dielectric layer functions as an electrical charge trapping medium. A conducting gate layer is placed over the upper silicon dioxide layer. A left and a right bit are stored in physically different areas of the charge trapping layer, near left and right regions of the memory cell, respectively. Each bit of the memory device is programmed in the conventional manner, using hot electron programming, by applying programming voltages to the gate and to either the left or the right region while the other region is grounded.

Abstract: A method for programming one or more reference cells is described. The reference cell is programmed a predetermined amount, its program state is sensed relative to a prescribed cell on the same die (e.g., a memory cell or a golden bit cell), and the programming process continues until the reference cell fails a preselected read operation. In one preferred embodiment, the memory cell used during the reference cell programming process is the cell in the memory array having the highest native threshold value. In another preferred embodiment, the memory cell used during the reference cell programming process is a native cell that is on-board the die containing the memory array, but not a cell within the memory array.

Abstract: An NROM memory cell is of a planar configuration without an additional oxidation being affected for the fabrication of the bit line oxide. The ONO layer is provided as a memory layer and is disposed with a uniform thickness on the semiconductor material of the source and drain regions and of the channel region, so that the ONO layer forms not only the gate dielectric, but also the insulation of the bit lines from the word lines or the gate electrode.

Abstract: A method for erasing a bit of a memory cell in a non-volatile memory cell array, the method comprising applying an erase pulse to at least one bit of at least one memory cell of the array, waiting a delay period wherein a threshold voltage of the at least one memory cell drifts to a different magnitude than at the start of the delay period, and after the delay period, erase verifying the at least one bit to determine if the at least one bit is less than a reference voltage level.

Abstract: A virtual ground array includes memory elements, select transistors, select lines connected with the select transistors, word lines, global bit lines and local bit lines connecting the select transistors with the memory elements, wherein each of the memory elements has a source and a drain, the virtual ground array is operative to select a set of memory elements and to fix the drains of the set of memory elements to a predetermined potential, the word lines and at least two of the select transistors select the set of memory elements and the global bit lines connect the select transistors to source and drain power supplies.

Abstract: A method for operating bits of memory cells in a memory array, the method including applying operating pulses to bits of a sample of memory cells, determining a response of at least one of an electrical, physical and mechanical property (e.g., threshold voltage) of the bits to the operating pulses, and applying at least one further operating pulse to the rest of the array, the at least one further operating pulse being a function of the response.

Abstract: A method for programming a reference cell of a memory array includes the steps of programming the reference cell with large programming steps until a threshold voltage level of the reference cell is above an interim target level and programming said reference cell with small programming steps until the threshold voltage level is above a final target level.

Abstract: A die for a memory array may store Flash and EEPROM bits in at least one Nitride Read Only Memory (NROM) array. Each array may store Flash, EEPROM or both types of bits.

Abstract: A memory cell has two diffusion areas in a substrate with a channel therebetween. The memory cell also includes a trapping dielectric layer at least over the channel, a gate at least above the trapping dielectric layer, and an implant in the substrate adapted to provide maximal band-to-band tunneling during erasure of charge stored in the trapping dielectric layer.

Abstract: A programmable, read only memory device includes two diffusion areas in a substrate and a channel formed therebetween, an oxide-nitride-oxide (ONO) layer comprising a first oxide layer overlaid by a nitride layer overlaid by a second oxide layer, the nitride layer having a thickness of 100 Angstroms or less and having two charge storage areas therein, each having a narrow width so that, during a read operation, current flows under the charge storage area not being read and a gate.

Abstract: A method for erasing a non-volatile memory cell array, the method including applying an erase pulse to at least one bit of at least one memory cell of the array, erase verifying the at least one bit with a first erase verify level, and if the bit has passed the first erase verify level, applying at least one more erase pulse to the at least one bit.

Abstract: An electrically erasable programmable read only memory (EEPROM) having a non conducting charge trapping dielectric, such as silicon nitride, sandwiched between two silicon dioxide layers acting as electrical insulators is disclosed. The invention includes a method of programming, reading and erasing the EEPROM device. The non conducting dielectric layer functions as an electrical charge trapping medium. A conducting gate layer is placed over the upper silicon dioxide layer. The memory device is programmed in the conventional manner, using hot electron programming, by applying programming voltages to the gate and the drain while the source is grounded. Hot electrons are accelerated sufficiently to be injected into the region of the trapping dielectric layer near the drain. The device, however, is read in the opposite direction from which it was written, meaning voltages are applied to the gate and the source while the drain is grounded.

Abstract: A method for operating an electrically erasable programmable read only memory (EEPROM) array, the method including refreshing a threshold voltage of a bit of a memory cell in an EEPROM array, the threshold voltage being different than a previous threshold voltage, by restoring the threshold voltage of the bit at least partially back to the previous threshold voltage.

Abstract: A memory array includes a first plurality of metal lines, a second plurality of diffusion bit lines and a third plurality of select transistors. There are more than two diffusion bit lines per metal bit line. The memory also includes a cell area formed of four segmented cell bit lines an even select area and an odd select area. The even select area is located at one end of the cell area and includes a segmented even contact bit line and two select transistors connecting the even contact bit line with the even cell bit lines of the segment. The odd select area is located at the opposite end of the cell area and includes a segmented odd contact bit line and two select transistors connecting the odd contact bit line with the odd cell bit lines of the segment.

Abstract: A symmetric segmented array has select transistors and column select transistors. At least one of the select and/or column select transistors is a low threshold voltage device. Alternatively, at least one select transistor and/or column select transistor of the array has a channel length shorter than a standard channel length of a process.

Abstract: A protection device which is active during the manufacturing process of a semiconductor chip includes a protection transistor and an antenna. The protection transistor is connected between a metal line having devices to be protected electrically connected thereto and a ground supply, where the metal line is connected to devices to be protected. The antenna is formed of the same metal layer as the metal line and controls the operation of the protection transistor during the manufacturing process. The antenna is connected to a gate of the protection transistor. Optically, there is a metal ring around the antenna which is connected to a drain of the protection transistor via the same metal layer as the metal line. During normal operation of the chip, the protection transistor is either active for other purposes or is turned off.

Abstract: A method for operating an electrically erasable programmable read only memory (EEPROM) array includes providing an array including a multiplicity of memory cells, wherein each memory cell is connected to a word line and to two bit lines, selecting one of the memory cells, and erasing a bit of thief selected memory cell while applying an inhibit word line voltage to a gate of an unselected memory cell. An EEPROM array is also described, the array including a multiplicity of NROM memory cells, wherein each memory cell is connected to a word line and to two bit lines, and wherein each NROM cell is individually erasable and individually programmable without significantly disturbing unselected cells.

Abstract: A method for operating bits of memory cells in a memory array, the method including applying operating pulses to bits of a sample of memory cells, determining a response of at least one of an electrical, physical and mechanical property (e.g., threshold voltage) of the bits to the operating pulses, and applying at least one further operating pulse to the rest of the array, the at least one further operating pulse being a function of the response.

Abstract: A method for forming a non-volatile memory device, the method including forming an oxide-nitride-oxide (ONO) layer over a portion of a substrate, the ONO layer including a bottom oxide layer, a top oxide layer and a nitride layer intermediate the bottom and top oxide layers, and managing movement of at least one of electrons and holes from the substrate towards the ONO layer by controlling a thickness of at least one of the bottom oxide layer, the nitride layer and the top oxide layer, wherein the top oxide layer is at least 1.5 times thicker than the bottom oxide layer. Non-volatile memory devices constructed in accordance with methods of the invention are also described.