Stmicroelectronics S.r.l.

Sgs-thomson Microelectronics S.r.l.

Other

Cesare Clementi

Gabriella Ghidini

Giuseppe Paolo Crisenza

Carlo Riva

Alessia Pavan

Livio Baldi

Alessandro Grossi

Marina Tosi

Maurizio Moroni

Federico Pio

Giorgio Servalli

Carlo Cremonesi

Nicola Zatelli

Mauro Alessandri

A method manufactures a non-volatile memory device on a semiconductor substrate that includes a matrix of memory cells and associated circuitry. The method includes: forming a filling dielectric layer on the whole substrate until gates of the cells and a conductive layer of the circuitry are completely covered, removing the dielectric layer until upper portions of the gates of the cells and the conductive layer are exposed, defining a plurality of gate electrodes of the transistors of the circuitry in the conductive layer, and forming source and drain regions of the transistors of the circuitry in the substrate. The method also comprises: forming spacers on side walls of gate electrodes of the transistors of the circuitry, and forming a silicide layer on the electrodes of the cells, on the gate electrodes of the transistors of the circuitry and on the source and drain regions of the transistors of said circuitry.

Method for manufacturing electronic non-volatile memory devices integrated in a semiconductor substrate

A semiconductor substrate has active areas bounded by portions of an insulating layer. A thin layer of tunnel oxide is formed on the substrate and a first layer of conductive material is then deposited. Non-volatile memory cells are manufactured thereon by defining floating gate regions. The definition of these floating gate regions involves defining the first layer of conductive material in order to form a plurality of alternated stripes above pairs of active areas alternated by active areas lacking stripes. Spacers are then formed in the shelter of the side walls of the alternated stripes. A second layer of conductive material is then deposited together with the first layer of conductive material. The spacers are then selectively removed.

Method for manufacturing non-volatile memory cells on a semiconductor substrate

A method is described for manufacturing non-volatile memory cells on a semiconductive substrate having active areas bounded by portions of an insulating layer. A thin layer of tunnel oxide is formed and a first layer of conductive material is then deposited. A plurality of floating gate regions are defined by forming stripes of shielding material only above pairs of alternated active areas. Spacers of a selective material are defined with respect to the shielding material and of small width at will in the shelter of the side walls of the stripes thus defined. A shielding material is also deposited on the active areas which lacked it. The formation of the floating gate is completed by leaving the definition of the distance between the floating gate regions to the spacers.

Process for forming salicide on active areas of MOS transistors, each MOS transistor comprising a gate and respective source and drain regions, the source and drain regions each comprising a first lightly doped sub-region adjacent the gate and a second highly doped sub-region spaced apart from the gate. The salicide is formed selectively at least over the second highly doped sub-regions of the source and drain regions of the MOS transistors, and not over the first lightly doped sub-region.

Process for the selective formation of salicide on active areas of MOS devices

A process for the manufacturing of electronic devices, including memory cells, involving forming, on a substrate of semiconductor material, multilayer stacks including a floating gate region, an intermediate dielectric region, and a control gate region; forming a protective layer extending on top of the substrate and between the multilayer stacks and having a height at least equal to the multilayer stacks. The step of forming multilayer stacks includes the step of defining the control gate region on all sides so that each control gate region is completely separate from adjacent control gate regions. The protective layer isolates the multilayer stacks from each other at the sides. Word lines of metal extend above the protective layer and are in electrical contact with the gate regions.

Electronic devices with nonvolatile memory cells of reduced dimensions

Process for manufacturing electronic devices comprising nonvolatile memory cells of reduced dimensions

A process of fabricating a floating-gate memory device, the process including the steps of: forming a stack of superimposed layers including a floating gate region, a dielectric region, and a control gate region; and forming an insulating layer of oxynitride to the side of the floating gate region to completely seal the floating gate region outwards and improve the retention characteristics of the memory device. The insulating layer is formed during reoxidation of the sides of the floating gate region, after self-align etching the stack of layers and implanting the source/drain of the cell.

Nonvolatile floating-gate memory devices, and process of fabrication

The driving capability of a selection transistor is increased by an N-type implant at the source and drain regions of the selection transistor itself. This implant is conveniently made at the end of the self-aligned etching, using the same self-aligned etching mask defining the control gate regions and the floating gate regions of memory elements, keeping the circuitry area covered by a circuitry mask.

Process for manufacturing selection transistors for nonvolatile serial-flash, EPROM, EEPROM and flash-EEPROM memories in standard or AMG configuration

A process for forming an integrated circuit includes at least one matrix of non-volatile memory cells having an intermediate dielectric multilayer including at least a lower dielectric material layer and an upper silicon oxide layer. The integrated circuit includes at least one transistor simultaneously formed in zones peripheral to the matrix and having a gate dielectric of a first thickness. After formation of the floating gate with a gate oxide layer and a polycrystalline silicon layer and the formation of the lower dielectric material layer, the process includes removal of said layers from the peripheral zones of the matrix; deposition of said upper silicon oxide layer over the memory cells, and over the substrate in the areas of the peripheral transistors; and formation of a first silicon oxide layer at least in the areas of the peripheral transistors. A second transistor type can be formed having a gate dielectric of a second thickness, thinner than said first thickness, in successive steps.

Process for forming an integrated circuit comprising non-volatile memory cells and side transistors and corresponding IC

The method described provides for the formation of thin thermal oxide on areas of a silicon die intended for memory cells and other components of the peripheral circuits of the memory. To improve the quality of the oxide of the cells essentially in terms of resistance to degradation due to the passage of charges through it during the operation of the memory, the method provides for a step for the high-temperature nitriding of the oxide. According to a variant, the nitrided oxide formed on the areas intended for the components of the peripheral circuits is removed and then formed again by a similar thermal oxidation treatment followed by high-temperature nitriding.

Method of manufacturing a MOS integrated circuit having components with

Process for forming an integrated circuit comprising non-volatile memory

A non-volatile integrated device having first and second dimensionally different polysilicon gate layers separated by an oxide layer for hot-carrier reliability. More specifically, the oxide and second polysilicon gate layer are selectively etched to form a second gate region over the first polysilicon gate layer that electrically contacts the first polysilicon gate in one direction and is isolated by the oxide in the other direction. Insulating sidewalls are formed over the first polysilicon gate layer regions that are not electrically contacted by the second gate layer to help isolate the second polysilicon gate and form an LDD structure within the substrate for the device.

Non-volatile integrated low-doped drain device with partially

A process or forming an integrated circuit calls for the provision of at least one matrix of non-volatile memory cells including an intermediate dielectric multilayer comprising a lower silicon oxide layer, an intermediate silicon nitride layer and an upper silicon oxide layer. The process calls for the simultaneous provision in zones peripheral to the memory cells of at least one first and one second transistor type each having a gate dielectric of a first and a second thickness respectively. After formation of the floating gate of the cells with a gate oxide layer and a polycrystalline silicon layer and the formation of the lower silicon oxide layer and of the intermediate silicon nitride layer, the process in accordance with the present invention includes removal of said layers from the zones peripheral to the matrix, and formation of a first silicon oxide layer over the substrate in the areas of both types of transistor. The process further includes removal of the preceding layer from areas assigned only to the transistors of the second type; deposition of said upper silicon oxide layer over the memory cells, over the first silicon oxide layer in the areas of the transistors of the first type and over the substrate in the areas of the transistors of the second type; and formation of a second silicon oxide layer in the areas of both types of peripheral transistors.

A method comprising the steps of depositing a first and second polysilicon layer, separated by an oxide layer; selectively etching the second polysilicon layer to form first gate regions; forming first substrate regions in the substrate and laterally in relation to the first gate regions; selectively etching the first polysilicon layer to form second gate regions of a length greater than the first gate regions; and forming in the substrate, laterally in relation to the second gate regions and partially overlapping the first substrate regions, second substrate regions of a higher doping level than the first substrate regions.

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Busto Arsizio, Italy

Cesare Clementi