Abstract: A method of manufacturing an integrated semiconductor device having at least one non-volatile floating gate memory cell and at least one logic transistor. The method includes growing a first gate oxide layer over a silicon substrate, depositing a first polysilicon layer over the first gate oxide layer, selectively etching and removing the first polysilicon layer in order to define the floating gate of the memory cell, introducing dopant in order to obtain source and drain regions of the memory cell, depositing a dielectric layer, selectively etching and removing the dielectric layer and the first polysilicon layer in a region wherein the logic transistor will be formed, depositing a second polysilicon layer, selectively etching and removing the second polysilicon layer in order to define the gate of the logic transistor and the control gate of the memory cell.

Abstract: A method of manufacturing an integrated semiconductor device having at least one non-volatile floating gate memory cell and at least one logic transistor. The method includes growing a first gate oxide layer over a silicon substrate, depositing a first polysilicon layer over the first gate oxide layer, selectively etching and removing the first polysilicon layer in order to define the floating gate of the memory cell, introducing dopant in order to obtain source and drain regions of the memory cell, depositing a dielectric layer, selectively etching and removing the dielectric layer and the first polysilicon layer in a region wherein the logic transistor will be formed, depositing a second polysilicon layer, selectively etching and removing the second polysilicon layer in order to define the gate of the logic transistor and the control gate of the memory cell.

Abstract: A method of forming high-stability metallic contacts in an integrated circuit with one or more metallized layers wherein, after a preliminary step of providing contact holes in a layer of dielectric material: a prebarrier layer of Ti or TiN is formed overall; a layer of tungsten is formed by chemical vapor deposition so as to coat the bases and the walls of the contact holes uniformly; aluminum or an alloy thereof is sputter-deposited, under high-temperature low-flux conditions, to fill the contact holes; and patterning the aluminum and tungsten layers to form metallic interconnections of predetermined geometry.

Abstract: A high voltage capacitor, integratable monolithically on a semiconductor substrate which accommodates a field oxide region overlaid by a first layer of polycrystalline silicon isolated from a second layer of polycrystalline silicon by an interpoly dielectric layer, comprises two elementary capacitors having a first common conductive plate which is formed in the first layer of polycrystalline silicon. Each of these elementary capacitors has a second conductive plate formed in the second layer of polycrystalline silicon above the first plate, and includes said interpoly dielectric layer as an isolation dielectric between the two plates.

Abstract: The present invention concerns an electrically programmable and erasable non-volatile memory cell having a traditional structure but being inverted in the conductivity type of the component elements and lacking the second source diffusion.

Abstract: The microtips of charge emitting material, which define the cathode of the flat FED screen and face the grid of the screen, are tubular and have portions with a small radius of curvature. The microtips are obtained by forming openings in the dielectric layer separating the cathode connection layer from the grid layer, depositing a conducting material layer to cover the walls of the openings, and anisotropically etching the layer of conducting material to form inwardly-inclined surfaces with emitting tips. Subsequently, the portions of the dielectric layer surrounding the microtips are removed.

Abstract: A process for forming a microtip cathode structure on a field emission display panel which avoids the need of vacuum depositing a lift-off layer for the microtip deposition overstructure in specially equipped reactors to accomplish a deposition at a grazing angle, by co-patterening the lift-off layer together with an underlying metal grid layer using a succession of different etching steps through the openings of a grid definition mask. According to an embodiment, nickel is used as lift-off material and is either wet-etched or sputter-etched before performing a plasma etch of the underlying grid metal layer. According to an alternative embodiment, the masking resist layer is used as lift-off material.

Abstract: A CMOS device and process are disclosed in which two types of N-channel MOS transistors are provided, one being formed in a P-well and one being formed outside the P-well where the relatively low doping concentration of P-type substrate serves as a channel defining region. This second type N-channel transistor an support higher junction voltages due to the lower p-type doping concentration than is possible for the first type N-channel transistor formed in the higher doping concentration P-well. A mask is provided to prevent boron doping in the substrate at the site of the high voltage transistor during the implantation step which defines the P-well.

Abstract: A pixel emission current limiting resistance is realized by forming a stack of alternately doped amorphous or polycrystalline silicon layers over the cathodic conductors of a FED driving matrix. The stack of amorphous or polycrystalline silicon layers doped alternately n and p provides at least a reversely biased n/p junction having a leakage current that matches the required level of pixel emission current. The reversely biased junction constitutes a nonlinear series resistance that is quite effective in limiting the emission current through any one of the microtips that form an individually excitable pixel and which are formed on the uppermost layer of the stack.

Abstract: A process including the steps of forming a gate oxide layer on a semiconductor substrate; masking the gate oxide layer with a nitride mask forming openings in the gate oxide layer using the nitride mask; and forming, at the openings, tunnel oxide regions of a thickness smaller than the thickness of the gate oxide layer. The nitride mask presents a thickness smaller than the width of the openings to improve etching of the gate oxide layer and subsequent washing. The mask also protects the covered layers when etching the gate oxide and growing the tunnel oxide regions, and is removed easily without damaging the exposed layers.

Abstract: A programming voltage is supplied to a control gate of a non-volatile memory cell via a control gate line. A supply voltage is coupled to a first plate of a capacitor and a reference voltage is coupled to a second plate of the capacitor. The supply voltage is then uncoupled from the first plate and the reference voltage is uncoupled from the second plate. Next, the reference voltage is coupled to the first plate to generate the programming voltage on the second plate.

Abstract: ROM memories made in MOS or CMOS technology with LDD cells may be programmed advantageously in a relatively advanced stage of fabrication by decoupling an already formed drain region from the channel region of cells to be permanently made nonconductive (programmed) by implanting a dopant in an amount sufficient to invert the type of conductivity in a portion of the drain region adjacent to the channel region. In CMOS processes, the programming mask may be a purposely modified mask commonly used for implanting source/drain regions of transistors of a certain type of conductivity. By using high-energy implantation and a dedicated mask, the programming may be effected at even later stages of the fabrication process.

Abstract: The present invention relates to a memory device and specifically the multilevel type with error check and correction function and having a data input (DI), a data output (DO) and an address input (A1) and being of the type comprising first memory, circuit (DM) designed to be accessed by means of address for containing user data, second memory circuit (EM) for containing error data concerning said user data, a control logic (CL) designed to receive in the writing phase from said address input (A1) and the data input (DI) a writing address and user data respectively and to generate error data and to write, the data in the first circuit (DM) and second circuit (EM) respectively and designed to receive in the reading phase from said address input (AI) a reading address and extract corresponding user data and error data and combine them to correct any errors and supply them to the data output (DO) and characterized in that the second, circuit (EM) is the type designed to be accessed by means of content and, the c

Abstract: Nonuniformities of luminance characteristics in a field emission display (FED) are compensated pixel by pixel by storing a matrix of correction values, determined by testing, and by applying a corrected drive signal through the relative column drive stages. The individual pixel's correction factor that is applied to the corresponding video signal may be stored in digital or analog form in a nonvolatile memory array. Various embodiments are described including the use of a second updatable RAM array wherein pixel's correction factors are calculated and stored at every power-on to provide an opportunity of trimming-up the luminance of the display for compensating long term decline of luminance due to the phosphors ageing process.

Abstract: A programming voltage is supplied to a control gate of a non-volatile memory cell via a control gate line. A supply voltage is coupled to a first plate of a capacitor and a reference voltage is coupled to a second plate of the capacitor. The supply voltage is then uncoupled from the first plate and the reference voltage is uncoupled from the second plate. Next, the reference voltage is coupled to the first plate to generate the programming voltage on the second plate.

Abstract: A process for forming low threshold voltage P-channel MOS transistors in semiconductor integrated circuits for analog applications, said circuits including high resistivity resistors formed in a layer of polycrystalline silicon and N-channel MOS transistors having active areas which have been obtained by implantation in a P-type well, comprises the steps of,providing a first mask over both said resistors and the semiconductor regions where the low threshold voltage P-channel transistors are to be formed,doping the polycrystalline layer uncovered by said first mask,providing a second mask for protecting the resistors and the semiconductor regions where said low threshold voltage P-channel transistors are to be formed, andN+ implanting the active areas of the N-channel transistors.

Abstract: A process for forming low threshold voltage P-channel MOS transistors in semiconductor integrated circuits for analog applications, said circuits including high resistivity resistors formed in a layer of polycrystalline silicon and N-channel MOS transistors having active areas which have been obtained by implantation in a P-type well, comprises the steps of,providing a first mask over both said resistors and the semiconductor regions where the low threshold voltage P-channel transistors are to be formed,doping the polycrystalline layer uncovered by said first mask,--providing a second mask for protecting the resistors and the semiconductor regions where said low threshold voltage P-channel transistors are to be formed, andN+ implanting the active areas of the N-channel transistors.

Abstract: A programming voltage is supplied to a control gate of a non-volatile memory cell via a control gate line. A supply voltage is coupled to a first plate of a capacitor and a reference voltage is coupled to a second plate of the capacitor. The supply voltage is then uncoupled from the first plate and the reference voltage is uncoupled from the second plate. Next, the reference voltage is coupled to the first plate to generate the programming voltage on the second plate.

Abstract: ROM memories made in MOS or CMOS technology with LDD cells may be programmed advantageously in a relatively advanced stage of fabrication by decoupling an already formed drain region from the channel region of cells to be permanently made nonconductive (programmed) by implanting a dopant in an amount sufficient to invert the type of conductivity in a portion of the drain region adjacent to the channel region. In CMOS processes, the programming mask may be a purposely modified mask commonly used for implanting source/drain regions of transistors of a certain type of conductivity. By using high-energy implantation and a dedicated mask, the programming may be effected at even later stages of the fabrication process.

Abstract: Highly reliable direct contacts may be formed by defining a direct contact area within a larger area purposely implanted and diffused for ensuring electrical continuity in the semiconductor. Patterning may define the contacting polysilicon within an implanted direct contact area so that the definition edges thereof fall on a gate oxide layer thus preventing an etching of the semiconductor during the unavoidable over-etching that concludes the polysilicon patterning step. Preferably, a pre-definition of the direct contact area is performed through a first, deposited layer of polysilicon, which effectively protects a gate oxide layer during a HF wash prior to depositing a second, contacting layer of polysilicon of adequate thickness.