Abstract: This invention relates to the fabrication of integrated circuit devices and more particularly to a method for minimizing the localized mechanical stress problems that can occur when silicided polysilicon gates are used to fabricate narrow channel CMOS devices. The invention addresses the avoidance of typical stress-induced problems in polysilicon gates, such as non-uniform silicide (including bowing, thinning edges, etc.) and voids, which are becoming increasingly worse as gate lengths continue to be reduced. The key to this invention is to spread the highly detrimental mechanical stresses, in narrow silicided gates, over a larger vertical surface area. This is accomplished by using a thin/thick double polysilicon stack for the gate, whereby, the lower thin polysilicon gate layer is not silicided and the upper thick polysilicon layer is subsequently silicided. An insulating layer is used to prevent silicidation of the lower thin polysilicon gate, during silicidation of active source-drain regions.

Abstract: A new method is provided for the creation of an ESD protection device for deep submicron semiconductor technology. An STI trench is created and filled with oxide. The surface of the STI region is polished after which a gate structure is created over the STI region. A high energy ESD implant is performed that is self-aligned with the created gate structure after which the EDS device structure is completed by implanting the source and drain regions of the ESD device.

Abstract: A method for creating low intra-level dielectric interface between conducting lines using conventional deposition and etching processes. A layer of conducting lines is formed interspersed with dielectric material. A dummy, high-density pattern of low k dielectric material is created on top of this layer. The dielectric material between the metal lines is removed. The dummy high-density pattern is interconnected, deposited on top of this interconnected layer is a low k dielectric to form an inter layer dielectric.

Abstract: A capacitor element of a semiconductor device used for high density semiconductor circuits is formed by the steps of forming the bottom plate of the capacitor, submitting the top of the bottom plate to plasma treatment in an oxidizing medium where nitrogen and oxygen are present, depositing a dielectric layer and submitting the top of the dielectric layer to plasma treatment in an oxidizing medium where nitrogen and oxygen are present. Various materials are used for the plasma treatment in an oxidizing medium where nitrogen and oxygen are present. While the present invention uses amorphous silicon as the dielectric material, plasma treatment in an oxidizing medium where nitrogen and oxygen are present can readily applied to a number of other dielectric materials.

Abstract: A structure and method for making copper interconnections in an integrated circuit are described. The structure is a damascene copper connector whose upper surface is coplanar with the upper surface of the insulating layer in which it is embedded. Out-diffusion of copper from the connector is prevented by two barrier layers. One is located at the interface between the connector and the insulating layer while the second barrier is an insulating layer which covers the upper surface of the connector. The damascene process involves filling a trench in the surface of the insulator with copper and then removing the excess by chem.-mech. polishing. Since photoresist is never in direct contact with the copper the problem of copper oxidation during resist ashing has been effectively eliminated.

Abstract: An improved and new method for fabricating conducting vias between successive layers of conductive interconnection patterns in a semiconductor integrated circuit has been developed. The method utilizes a first CMP step to form a barrier lined contact hole, deposition of copper by electroless plating into the barrier lined contact hole, and a second CMP step to remove overgrowth of copper, thus producing coplanarity between the copper surface and the surrounding insulator surface.

Abstract: A new method of forming a butted contact and a buried contact having low contact resistance in the fabrication of integrated circuits is described. A first layer of polysilicon is deposited over a gate silicon oxide layer over the surface of a semiconductor substrate. The first polysilicon and gate oxide layers are etched away to provide an opening to the substrate. A second polysilicon layer is deposited over the first polysilicon layer and the substrate within the opening and doped whereby the buried contact junction is formed in the substrate underlying the doped second polysilicon layer. The second polysilicon layer is planarized. The first and second polysilicon layers are etched away to provide an opening overlying a portion of the buried contact junction wherein a trench is etched into the substrate where the substrate is not covered by the gate oxide layer. An oxide layer is deposited over the second polysilicon layer and within the trench.

Abstract: A process for curing low-k spin-on dielectric layers based on alkyl silsesquioxane polymers by laser scanning is described wherein curing is achieved by both photothermal and photochemical mechanisms. The layers are deposited by spin deposition, dried and cured by raster scanning with a pulsed laser at energies between 0.1 and 1 Joules/cm.sup.2. Because the laser causes heating of the layer, a nitrogen jet is applied in the wake of the scanning laser beam to rapidly cool the layer and to inhibit oxidation and moisture absorption. The laser induced heating also assists in the discharge of moisture and by-products of the polymerization process. The laser operates at wavelengths between 200 and 400 nm. Insulative layers such as silicon oxide are sufficiently transparent at these so that oxide segments overlying the polymer layer do not inhibit the curing process. Implementation of the laser scanning feature is readily incorporated into an existing spin-on deposition and curing tool.

Abstract: A method of fabricating a MOS device having raised source/drain, raised isolation regions having isolation spacers, and a gate conductor having gate spacers is achieved. A layer of gate silicon oxide is grown over the surface of a semiconductor structure. A polysilicon layer is deposited overlying the gate silicon oxide layer. The polysilicon layer, gate silicon oxide layer and semiconductor structure are patterned and etched to form trenches. The trenches are filled with an isolation material to at least a level even with a top surface of the polysilicon layer to form raised isolation regions. The remaining polysilicon layer is patterned to remove polysilicon adjacent the raised isolation regions forming a gate conductor between the raised isolation regions. The gate conductor and the raised isolation regions having exposed sidewalls. The gate oxide layer between the gate conductor and raised isolation regions is removed.

Abstract: A method for planarizing metal plugs for device interconnections. The process begins by providing a semiconductor structure with at least one device thereon. A dielectric layer is formed over the device and the semiconductor structure. A first barrier metal layer is formed on the dielectric layer, and a sacrificial oxide layer is formed on the first barrier metal layer. The sacrificial oxide layer, the first barrier metal layer, and the dielectric layer are patterned to form contact openings. A second barrier metal layer is formed over the semiconductor structure, and a metal contact layer is formed on the second barrier metal layer. The metal contact layer and the second barrier metal layer are planarized using a first chemical mechanical polishing process and the sacrificial oxide layer is removed. The metal contact layer and the first barrier metal layer are planarized using a second chemical mechanical polishing process.

Abstract: A method of forming shallow trench isolations is achieved. STI structures so formed do not exhibit isolation oxide thinning due to dishing and erosion problems during the oxide CMP process. A silicon substrate is provided. A first dielectric layer is formed overlying the silicon substrate. A silicon nitride layer is deposited. The silicon nitride layer, the first dielectric layer, and the silicon substrate are etched to form trenches for planned shallow trench isolations. A second dielectric layer is deposited overlying the silicon nitride layer and the trenches. The second dielectric layer is etched to form sidewall spacers inside the trenches. A silicon layer is selectively grown overlying the silicon substrate only where the silicon substrate is exposed in the trenches, and wherein the step of growing is stopped before the silicon layer exceeds the top surface of the silicon nitride layer.

Abstract: A method for making copper interconnections in an integrated circuit is described. The structure is a damascene copper connector whose upper surface is coplanar with the upper surface of the insulating layer in which it is embedded. Out-diffusion of copper from the connector is prevented by two barrier layers. One is located at the interface between the connector and the insulating layer while the second barrier is an insulating layer which covers the upper surface of the connector. The damascene process involves filling a trench in the surface of the insulator with copper and then removing the excess by chem.-mech. polishing. Since photoresist is never in direct contact with the copper the problem of copper oxidation during resist ashing has been effectively eliminated.

Abstract: An interconnect line on an IMD layer on a semiconductor device is formed in an interconnect hole in the IMD layer. The interconnect hole has walls and a bottom in the IMD layer. A diffusion barrier is formed on the walls and the bottom of the hole. Fill the interconnect hole with a copper metal line. Perform a CMP step to planarize the device and to remove copper above the IMD layer. Deposit a passivating metal layer on the surface of the copper metal line encapsulating the copper metal line at the top of the hole. Alternatively, a blanket deposit of a copper metal line layer covers the diffusion layer and fills the interconnect hole with a copper metal line. Perform a CMP process to planarize the device to remove copper above the IMD layer. Deposit a passivating metal layer on the surface of the copper metal line encapsulating the copper metal line at the top of the hole in a self-aligned deposition process.

Abstract: A method for fabricating a deep sub-micron gate electrode, comprising polysilicon and metal, having ultra-low sheet resistance. The process begins by forming shallow trench isolation regions 14 in a silicon substrate 10. A gate oxide layer is formed on device areas. A doped blanket polysilicon layer 16 is formed on the gate oxide layer. A cap layer 20 composed of silicon nitride is formed on the polysilicon layer 16. The cap layer 20 and the polysilicon layer 16 are patterned by photoresist masking and anisotropic etching to form a bottom gate electrode 16A and a gate cap 20A. Lightly doped source/drain areas 22 are formed adjacent to the gate bottom electrodes 16A by ion implantation. Sidewall spacers 21 are formed on the gate electrode 16A and gate cap 20A. Source/drain regions 24 are formed by ion implantation adjacent to said sidewall spacers 21. A metal silicide 23 is formed on the source/drain regions 24.

Abstract: A method for preserving the integrity of the underlying metal lines during planarization by inserting a nitride layer as an etch stop in an oxide-nitride-oxide dielectric layer underlying a spin-on polymer is described. Semiconductor device structures are provided in and on a semiconductor substrate. A conducting layer is deposited overlying the surfaces of the semiconductor device structures and patterned to form conducting lines wherein a gap is formed between the conducting lines. A first dielectric layer is deposited over the surfaces of the conducting lines wherein the first dielectric layer contains an etch stop layer wherein the gap remains between the conducting lines. A second dielectric layer is deposited overlying the first dielectric layer wherein the gap is filled by the second dielectric layer. The second dielectric layer is etched back so that the second dielectric layer remains only within the gap wherein the etch stop layer preserves the integrity of the underlying conducting lines.

Abstract: Small metallic patches embedded in a mainly non-metallic surface may be detected and mapped by placing a wire coil at the free end of a cantilever, with a fine tip made of a ferro-magnetic material located at its center. An alternating current is passed through the coil so that when it is near a metallic patch eddy currents are induced in the patch. These produce a small magnetic moment in the patch which pulls the tip towards the surface. This movement of the tip is detected by observing a light beam that is reflected off the surface of the cantilever. By plotting the output of a photodetector, sensistive to small changes in the reflected beam's position, as a function of the tip's location over the surface, a map of the metallic patches is produced.

Abstract: A new method of fabricating a stacked gate Flash EEPROM device having an improved interpoly oxide layer is described. A gate oxide layer is provided on the surface of a semiconductor substrate. A first polysilicon layer is deposited overlying the gate oxide layer. The first polysilicon layer is etched away where it is not covered by a mask to form a floating gate. Source and drain regions associated with the floating gate are formed within the substrate. An oxide layer is deposited overlying the floating gate and the substrate. The oxide layer is polished away until the top of the oxide layer is even with the top of the floating gate. A second polysilicon layer is deposited overlying the oxide layer and the first polysilicon layer of the floating gate wherein the second polysilicon layer has a smooth surface. An interpoly dielectric layer is deposited overlying the second polysilicon layer. A third polysilicon layer is deposited overlying the interpoly dielectric layer.

Abstract: A method was achieved for fabricating field oxide regions (shallow trench isolation) having raised portions which are self-aligned and extend over edges of device areas. This results in FETs with improved sub-threshold characteristics and lower sub-threshold leakage currents. The method consists of forming a pad oxide and depositing a doped polysilicon layer and a hard mask layer on a silicon substrate. Shallow trenches are etched through the hard mask, doped polysilicon layer and partially into the silicon substrate. A thermal oxidation is used to form a liner oxide in the trenches and to oxidize, at a higher oxidation rate, the sidewalls of the doped polysilicon layer to form an oxide over the edges of the device areas. A gap-fill oxide is deposited in the trenches and chemical mechanical polished (CMP) back to the polysilicon layer. The remaining polysilicon layer over the device areas is selectively removed to provide a field oxide having raised portions formed over the edges of the device areas.

Abstract: A method of planarizing integrated circuit wafers using chemical mechanical polishing with an automatic end point and without using an etchback step. An electrode pattern is formed in a layer of soft metal, such as Al/Cu/Si, capped with a layer of hard metal such as tungsten. A layer of first oxide, a layer of spin on glass, and a layer of second oxide are formed over the electrode pattern. The layer of first oxide, the layer of spin on glass, and the layer of second oxide are then planarized using chemical mechanical polishing. The hard metal cap on the electrode pattern can not be removed by the chemical mechanical polishing and forms an automatic end point. The electric current powering the motor driving the chemical mechanical polishing changes when the hard metal cap is reached and this change can be used to detect the end point.

Abstract: A method for fabricating an anti-fuse cell using an undoped polysilicon film as a mask in defining the anti-fuse window is described. A layer of silicon oxide is provided over the surface of a semiconductor substrate. A first undoped polysilicon layer is deposited overlying the silicon oxide layer. The first undoped polysilicon layer is covered with a photoresist layer patterned to form a mask. The first undoped polysilicon layer and a portion of the silicon oxide layer are etched away where they are not covered by the mask to form a cell opening. The mask and the remaining silicon oxide within the cell opening are removed. An insulating layer is deposited over the surface of the first undoped polysilicon layer and within the cell opening. A second polysilicon layer is deposited overlying the insulating layer and doped. The second polysilicon layer is patterned to form an anti-fuse cell. Gate electrodes and source and drain regions are formed completing the fabrication of the integrated circuit device.