摘要:
A process of fabricating a flash EEPROM having a NAND structure by using the liquid phase deposition (LPD) technique and self-alignment technique is disclosed to achieve higher density and reliability of flash memory cells and eliminating the shortcomings of the bird's beaks of field oxides.
摘要:
A method of fabricating an EPROM memory increases a coupling ratio and reduces lateral diffusion by forming a gate oxide layer and a coupling insulator individually. A substrate is provided with a field oxide layer to isolate a predetermined active area. A gate oxide layer is formed on the substrate. On the field oxide layer and the gate oxide layer, a polysilicon layer is deposited and defined, whereby a portion of this polysilicon layer and gate oxide layer form a gate electrode. Using the gate electrode as a mask, the substrate is implanted with impurities to provide source and drain electrodes. A dielectric layer is formed on polysilicon layer. A contact window (via) is formed in a predetermined area of dielectric layer. An insulator is deposited and defined by etching, on dielectric layer and the contact window. On the insulator and dielectric layer, a metal contact layer is deposited and defined to cover the insulator.
摘要:
A vertical split gate memory device has a semiconductor substrate with a trench and a floating gate formed on a sidewall of the trench, thus reducing the surface area of each memory cell. The fabrication process for this device allows precise control over the consistency during fabrication because the length of the floating gate is controlled by the depth of a trench etch and the location of the drains and sources are self-aligned by oxide spacers which act as masks during the doping process.
摘要:
A process for manufacturing bonding pad adapted for use with an aluminum wire that resists stresses that would otherwise peel the pad from the substrate. The pad has a polysilicon layer adhered to an insulating layer on a semiconductor substrate, a overlying refractory metal polycide layer, a second polysilicon layer, a refractory metal layer, and a thick aluminum alloy bonding pad.
摘要:
A method for forming, and a resultant structure of, a top floating gate FLASH EEPROM cell are described. There is a first insulating structure over a silicon substrate, whereby the first insulating structure is a gate oxide. A first conductive structure is formed over the first insulating structure, whereby the first conductive structure is a control gate. There is a first insulating layer over the surfaces of the first conductive structure, whereby the first insulating layer is an interpoly dielectric. There is a second conductive structure formed over the first insulating layer and over a portion of the silicon substrate adjacent to the first insulating structure, whereby the second conductive structure is a floating gate. A second insulating layer is formed between the silicon substrate and the second conductive structure, whereby the second insulating layer is a tunnel oxide. Active regions in the silicon substrate, implanted with a conductivity-imparting dopant, are formed under the second insulating layer but are horizontally a distance from the first insulating structure.
摘要:
A method for fabricating read only memory, (ROM), devices, has been developed. The programmable cell of this ROM device is comprised of a P/N diode, place in a N+ buried bit line. The diode formation is accomplished using outdiffusion from a P+ polysilicon wordline, that is in direct contact to a specific bit line region.
摘要:
A process for fabricating memory cells for split-gate flash memory devices is disclosed to feature self-alignment and therefore precisely defined channel lengths for the floating-gate and isolation transistors of the memory cell. A gate oxide layer, a first conducting layer, and a gate dielectric layer are formed in sequence on a semiconductor substrate. A conducting strip is formed on the gate dielectric layer. The conducting strip is covered with a shielding layer. The gate dielectric layer, the first conducting layer and the gate oxide layer are etched utilizing the shielding layer as a shielding mask to form a control gate for the memory cell. Thermal oxidation is applied to the entire substrate utilizing the shielding layer as a shielding mask to form a tunnel oxide layer on the surface of the substrate and isolating oxide layers on the sidewalls of the control gate. The shielding layer is removed. Electrically conducting sidewall spacers are formed on both of the sidewalls of the conducting strip. Each of the conducting sidewall spacers cover a portion of the tunnel oxide layer and are also electrically isolated from the control gate by the isolating oxide layer, forming the floating gate for the memory cell. Impurities are implanted utilizing the conducting strip and the conducting sidewall spacers as shielding masks to form source and drain regions on the substrate for the memory cell.
摘要:
A method of manufacturing an improved Read-Only-Memory (ROM) device, was achieved. The array of programmed ROM cells composed of field effect transistors (FETs) are fabricated having improved bit lines with lower resistance. The method utilizes the selective deposition of silicon oxide by a method of Liquid Phase Deposition (LPD) to form a thick insulating oxide layer over the gate oxide of the FET in the coded memory cells. The thick insulating oxide raises the threshold voltage of the FET, preventing the FET from turning on when a gate voltage is applied. The coding using a thick insulating oxide eliminates the need to code the ROM memory cells by ion implantation, and thereby prevents the counter-doping of the bit lines which results in the high bit line resistivity that degrades circuit performance.
摘要:
A method for fabricating read only memory, (ROM), devices, has been developed. The programmable cell of this ROM device is comprised of a P/N diode, place in a N+ buried bit line. The diode formation is accomplished using outdiffusion from a P+ polysilicon wordline, that is in direct contact to a specific bit line region.
摘要:
A method is desired for making an array of dynamic random access memory (DRAM) cells having stacked capacitors with increased capacitance. The method involves forming a bottom electrode having a lower and upper fin-shaped portion in which a vertical extension is formed on the lower fin-shape portion at the same time that the upper fin is formed. This increases the capacitance of the stacked capacitor. The bottom electrode is formed by patterning a thick expendable silicon oxide layer and an underlying doped polysilicon layer (lower fin portion). Another polysilicon layer (upper fin portion is conformally coated over the thick insulating layer and patterned with an etch mask, which is smaller than the patterned insulating layer. An anisotropic etch is performed that forms the upper fin portion, the vertical extension on the lower fin portion and electrically isolates the array of electrodes. The capacitors are then completed by removing the expendable oxide layer, forming a capacitor dielectric layer on the bottom electrode, and patterning a doped polysilicon layer for the top electrode of the stacked capacitor.