Abstract:
Submicron-dimensioned metallization patterns are formed on a substrate surface by a photo-activated selective, anisotropic etching process, wherein selective portions of a metal layer are exposed to collimated UV passing through a pattern of submicron-sized openings in an overlying exposure mask. At least one photo-activatable etching material contained in a gas flowed through the space between the substrate surface and the mask selectively and anisotropically etches the exposed portions of the metal layer in thereby avoiding numerous masking and etching steps as in conventional photolithographic methodology. The inventive method is of particular utility in performing multi-level, in-laid, “back-end” metallization processing of high-density integrated circuit semiconductor devices.
Abstract:
In one embodiment, the present invention relates to a method of forming a Silicon-on-Insulator substrate involving the steps of providing a monocrystalline silicon substrate; patterning a mask over the monocrystalline silicon substrate thereby exposing a portion of the monocrystalline silicon substrate; implanting a first dosage of oxygen atoms in the exposed portion of the monocrystalline silicon substrate; removing the mask from the monocrystalline silicon substrate; implanting a second dosage of oxygen atoms without using an implantation mask in the monocrystalline silicon substrate; and annealing the oxygen implanted monocrystalline silicon substrate to provide the Silicon-on-Insulator substrate. In another embodiment, the present invention relates to a Silicon-on-Insulator structure containing a monocrystalline silicon layer; a buried oxide layer over the monocrystalline silicon layer, the buried oxide layer including a first region having a first thickness and a second region having a second thickness, wherein the first thickness is from about 30% to about 70% smaller than the second thickness; a silicon device layer over the buried oxide layer; and a heat generating device on the silicon device layer and positioned over the first region of the buried oxide layer.
Abstract:
Low resistivity contacts are formed on source/drain regions and gate electrodes at a suitable thickness to reduce parasitic series resistances, thereby significantly reducing consumption of underlying silicon, while significantly reducing junction leakage. Embodiments include selectively depositing a metal layer, such as nickel, on the source/drain regions and on the gate electrode and ion implanting to form a barrier layer within the nickel layers which does not react with silicon or nickel silicide during subsequent solicitation. The barrier layer confines salicidation to the relatively thin underlayer layer of nickel, thereby minimizing consumption of underlying silicon while the unsilicidized overlying nickel on the barrier layer ensures low sheet resistivity.
Abstract:
A method for fabricating short channel field effect transistors with dual gates and with a gate dielectric having a high dielectric constant. The field effect transistor is initially fabricated to have a sacrificial gate dielectric and a dummy gate electrode. Any fabrication process using a relatively high temperature is performed with the field effect transistor having the sacrificial gate dielectric and the dummy gate electrode. The dummy gate electrode and the sacrificial gate dielectric are etched from the field effect transistor to form a gate opening. A layer of dielectric with high dielectric constant is deposited on the side wall and the bottom wall of the gate opening, and amorphous gate electrode material, such as amorphous silicon, is deposited to fill the gate opening. A reaction barrier layer is deposited between the gate dielectric with the high dielectric constant and the amorphous gate electrode material to prevent a reaction between the gate dielectric and the gate electrode material. Dual gates for both an N-channel field effect transistor and a P-channel field effect transistor are formed by doping the amorphous gate electrode material with an N-type dopant for an N-channel field effect transistor, and by doping the amorphous gate electrode material with a P-type dopant for a P-channel field effect transistor. The amorphous gate electrode material in the gate opening is then annealed at a relatively low temperature, such as 600.degree. Celsius, using a solid phase crystallization process to convert the amorphous gate electrode material, such as amorphous silicon, into polycrystalline gate electrode material, such as polycrystalline silicon.
Abstract:
A novel semiconductor fabrication process having the advantages of conventional LOCOS (process simplicity and reduced defects) while providing a scaleable, planar isolation region between active regions formed in a semiconductor substrate. The preferred process includes formation of a barrier layer and a masking layer over the substrate. An active region mask defines an exposure region of the masking layer. The exposure region is etched to form an opening, exposing a portion of barrier layer in the opening. A spacer is added inside the opening, around a perimeter of the opening to define a second exposure region. The barrier layer, and substrate, under the second exposure region, but not under the spacer, are etched to form an isolation region opening. The isolation region opening may have a suitable isolating material, such as silicon oxide, grown, filled, or some combination of both, in the isolation region opening. The spacer width and the depth of the isolation region opening are independently controllable.
Abstract:
A deep submicron MOS device having a self-aligned silicide gate structure and a method for forming the same is provided so as to overcome the problems of poly-Si depletion and boron penetration. A first Nickel silicide layer is formed between a gate oxide and a polycrystalline silicon gate electrode. Further, second Nickel silicide layers are formed over highly-doped source/drain regions. In this fashion, the reliability of the MOS device will be enhanced.
Abstract:
A method for producing a small feature in a semiconductor device includes depositing a mask material on an unpatterned layer in which an ultra-narrow opening is to be formed, and then masking and etching the mask material to form a narrow opening. A spacer material is then deposited on the mask material, with spacer material settling into and covering the narrow opening. Thereafter, a portion of the spacer material is removed by etching, leaving some spacer material in the opening but exposing an ultra-narrow region of the first layer at the bottom of the opening in the mask material. The ultra-narrow region left uncovered by the spacer material is smaller than the narrow region in the mask material. Once the ultra-narrow region is uncovered, material in the first layer is removed through the ultra-narrow region, by anisotropic etching, for example, to form an ultra-narrow opening in the first layer.
Abstract:
A method of manufacturing an MOS transistor having a gate length dimension less than the dimension available by methods available with conventional manufacturing methods that are limited by optical diffraction in photolithography. The method includes forming a polysilicon gate structure on a gate oxide layer, forming a nitrogen-doped layer on the polysilicon gate structure, forming selected depth oxide sidewalls on the polysilicon gate structure and etching the nitrogen-doped layer and the oxide sidewalls.
Abstract:
A multilayer semiconductor structure includes a conductive via. The conductive via includes a reservoir of metal having a high resistance to electromigration. The reservoir is made from a conformal layer of copper, or gold deposited over the via to form a copper, or gold plug located in the via. A barrier layer is provided between the reservoir and an insulating layer to prevent the reservoir from diffusing into the insulating layer. The barrier layer and reservoir may be deposited by sputtering, collimated sputtering, chemical vapor deposition (CVD), dipping, evaporating, or by other means. The barrier layer and reservoir may be etched by anisotropic dry etching, plasma-assisted etching, or other layer removal techniques.
Abstract:
Submicron contacts/vias and trenches are provided in a dielectric layer by forming an opening having an initial dimension and reducing the initial dimension by depositing a second dielectric material in the opening.