Abstract:
Trench capacitors are fabricated utilizing a method which results in a metallic nitride as a portion of a node electrode in a lower region of the trench. The metallic nitride-containing trench electrode exhibits reduced series resistance compared to conventional trench electrodes of similar dimensions, thereby enabling reduced ground rule memory cell layouts and/or reduced cell access time. The trench capacitors of the invention are especially useful as components of DRAM memory cells having various trench configuration and design.
Abstract:
A flash memory and a method of forming a flash memory, includes forming a polysilicon wordline on a substrate, the wordline having first and second sidewalls, the first sidewall being tapered, with respect to a surface of the substrate, to have a slope angle and the second sidewall having a slope angle greater than the slope angle of the first sidewall. Thereafter, a polysilicon spacer is formed on the second sidewall while simultaneously removing the polysilicon on the first sidewall. The polysilicon spacer forms a floating gate which is surrounded on a plurality of sides by the second sidewall.
Abstract:
A structure and process for fabricating a crown capacitor using a tapered etch and chemical mechanical polishing to form a bottom electrode having an increased area and crown is provided. The tapered etch is used to form a trough in an interlevel dielectric, e.g. SiO2, and is performed over contact hole forming a crown-like structure. The trough and, optionally, the crown are then covered by a conductor, which is patterned by chemical mechanical polishing.
Abstract:
A method for depositing materials on a surface, having the following steps: a) obtaining a surface having at least feature thereon, the surface and the feature having a layer of first material deposited thereon, the first material not filling substantially all of the feature; b) depositing a layer of a second material on the first material, wherein the melting point of the second material is less than that of the first material, and wherein the first material is soluble in the second material at a temperature less than the melting point of the first material; and c) heating the surface to a first temperature of at least equal to the melting point of the second material and at most equal to the melting point of the first material, wherein substantially all of the via is filled with the first material.
Abstract:
Provision of differential etching of layers by, for example, an etch stop layer or implantation, allows a second trough etch to be performed in accordance with a block-out mask (which does not require high accuracy of registration) to provide troughs or recesses of different depths in layers of insulator. When the recesses or troughs are filled by metal deposition and patterned by planarization in accordance with damascene processing, structurally robust conductors of differing thicknesses may be achieved and optimized to enhance noise immunity and/or signal propagation speed in different functional regions of an integrated circuit such as the so-called array and support portions of a dynamic random access memory.
Abstract:
Reduction of gate-induced-drain-leakage in metal oxide semiconductor (MOS) devices is achieved by performing an anneal in a non-oxidizing ambient. In one embodiment, the anneal is performed in a argon and/or ammonia ambients after gate sidewall oxidation that forms the spacers.
Abstract:
Electrical interconnection with studs is formed by depositing conductive stud material in contact holes in a dielectric layer; patterning the conductive stud material and removing a shallow portion of the dielectric layer surrounding the stud material; depositing a thin layer of dielectric material over the conductive stud and first dielectric layer; forming a trench in the dielectric layers and over the top of the stud material; and depositing conductive material in the trench.
Abstract:
The present invention provides a method for fabricating tungsten local interconnections in high density CMOS circuits, and also provides high density CMOS circuits having local interconnections formed of tungsten. Pursuant to the method, an etch stop layer of chromium is initially deposited on the circuit elements of the CMOS silicon substrate. Next, a conductive layer of tungsten is non-selectively deposited on the chromium layer. A photoresist mask is then lithographically patterned over the tungsten layer. The tungsten layer is then etched down to, and stopping at, the chromium layer, after which the photoresist mask is stripped. The stripping preferably uses a low temperature plasma etch in O.sub.2 at a temperature of less than 100.degree. C. Finally, a directional O.sub.2 reactive ion etch is used to remove the chromium layer selectively to the silicon substrate. Borderless contacts are formed with the aid of the chromium etch stop layer beneath the tungsten local interconnection layer. The method of integration of this approach results in anisotropic metal lines patterned over topography using a standard photoresist mask. This approach also allows partial overlap of contacts to reduce device dimensions, and thereby results in improved density and performance.
Abstract:
A method of manufacturing a bipolar transistor by use of low temperature emitter process is disclosed. After completion of the usual base and collector formation in a vertical bipolar transistor, an emitter opening is etched in the insulator layer over the base layer at selected locations. A thin layer (less than 500 .ANG.) of in-situ doped amorphous silicon is deposited over the substrate and heated to densify for 30 to 60 minutes at about 650.degree. C. Subsequently an in-situ doped polysilicon layer of 100 to 200 nm is deposited over the amorphous Si film preferably at about 600.degree. C. Subsequently the layers are heated below 600.degree. C. for several hours to convert partially the amorphous Si into a monocrystalline emitter layer over the base regions.
Abstract:
A temperature sensor, comprising: a diode structure including, a) a silicon substrate, b) a first region of a metal silicide in the silicon substrate, c) a second region of a metal-oxide semiconductor material on the first region, d) a third region of a metal over the second region; and, means for using the diode structure as a temperature sensitive device to measure an ambient temperature. The metal-oxide semiconductor material is preferably selected to have a bandgap of not less than about 3.0 eV.