Abstract: An improved vertical diffusion furnace for semiconductor manufacturing processes is provided. Temperature and flow rate management enables more uniform temperature distribution across the wafer during ramp up and ramp down, thereby preventing wafer warp.

Abstract: A method for forming a transistor comprises the steps of: forming a gate stack on the surface of a semiconductor substrate; implanting a first dose of an impurity into the substrate at a sufficient energy to penetrate at least a portion of the gate stack to provide a portion of the impurity on the first and second sides of the gate stack, and a portion of the impurity under the gate stack; and forming source/drain regions on the first and second sides of the gate stack. The implant may be at an angle normal to the surface of the substrate at an energy sufficient such that the impurity penetrates the gate stack to reach the channel region. Alternatively, a pair of angled implants at an angle relative to a line normal to the surface of the substrate may be used.

Abstract: An SRAM memory cell device is provide having a single transistor and a single RTD latch structure. The single transistor and RTD latch structure are formed on a very thin silicon layer, typically in the range of 250 to 300 Å thick, allowing for increased memory cell density over a given area. The RTD latch structure is a lateral RTD device, such that the outer contacting regions, the tunneling barriers and the central quantum well are formed side-by-side as opposed to being stacked on top of one another. This allows for formation of the memory cell device on very thin silicon layers. The layers can then be stacked to form memory devices for use with computers and the like. The memory device can be formed employing silicon-on-insulator (SOI) technology to take advantage of SOI device characteristics.

Abstract: A method/system for forming a resonant tunneling diode latch is disclosed. The method/system comprises the steps of forming a gate on a silicon substrate, the silicon substrate having at least one SOI layer disposed therein, providing an oxide spacer over the gate, providing a first ion implant in a first region of the silicon substrate, and then providing an oxide layer. The method further comprises polishing the oxide back to the gate, removing the gate, providing a second ion implant in a second region of the silicon substrate wherein the first and second regions have an undoped portion of silicon there between. According to the present invention, the method/system for forming a resonant tunneling diode latch in an SOI substrate that is easily implemented and results in an increased throughput of resonant tunneling diode devices.

Abstract: The present invention provides a fabrication process for fabricating an integrated circuit substrate structure having LOCOS isolation areas formed such that oxidation encroachment at an active surface region patterned on the substrate is less than 0.1 &mgr;m. The fabrication process includes various process steps for forming a 0.75 &mgr;m. to 1.0 &mgr;m layer of silicon dioxide (SiO2) over thin layers of silicon dioxide (0.01 &mgr;m. to 0.05 &mgr;m) and silicon nitride (0.05 &mgr;m. to 0.10 &mgr;m) over a surface region of the substrate to form a protective stack/passivation layers over a surface region of the silicon substrate. The protected substrate surface region is useable for fabricating a microelectronic circuit device, such as a MOS transistor, or a flash memory device. Adjacent the protective stack, a silicon nitride spacer region is formed to effectively widen the protected substrate surface region.

Abstract: A totally self-aligned transistor with a tungsten gate. A single mask is used to align the source, drain, gate and isolation areas. Overlay error is greatly reduced by the use of a single mask for these regions. A mid-gap electrode is also self-aligned to the transistor. The electrode is preferably formed from tungsten metal.

Abstract: An integrated circuit process technology for simultaneously forming multiple threshold voltage devices is disclosed. Devices having both high speed and low power consumption can be fabricated for use in integrated circuits having a need for both, such as microprocessors having cache memory.

Abstract: A channel region is formed in a device after the source and drain regions are formed by implanting ions into the channel region with a tilt angle using multiple rotations. A rapid thermal annealing step is performed to activate the channel dopant. Because the source and drain regions are already formed, a relatively low temperature, e.g., 990 to 1010 degrees Celsius, and short, e.g., 1 to 5 seconds, rapid thermal annealing step may be performed to activate the channel region. Thus, the dopant concentration in the channel region may be well localized and accurately controlled.

Abstract: Channel doping is implemented such that dopants remain localized under the gate without migrating under the source/drain juctions during processing, thereby avoiding performance degradation of the finished device. Embodiments include implanting impurities at an acute angle to form a lateral channel implant localized below the gate after activation of source/drain regions, and activating the lateral channel implant by a low-temperature RTA during subsequent metal silicide formation. The use of a low-temperature RTA for electrical activation of the lateral channel implant avoids impurity migration under the source/drain junctions, thereby lowering parasitic junction capacitance and enabling the manufacture of semiconductor devices exhibiting higher circuit speeds with improved threshold voltage control.

Abstract: In manufacturing a transistor, a doping mask is formed above a substrate. The doping mask is constructed, so that a first region of the substrate for serving as a source in the transistor and a second region of the substrate for serving as a drain in the transistor are substantially shielded. Once the doping mask is formed, ions are introduced into a region in the substrate that is to underlie the transistor's gate structure. The ions are introduced to establish the characteristics of the transistor, such as the transistor's threshold voltage and punch-through breakdown voltage. After the ions are introduced, a gate oxide is formed to overlie a portion of the substrate. The gate structure for the transistor is then formed to substantially overlie the region of the substrate in which the ions have been introduced. Once a gate is formed for the gate structure, a source and drain are formed in the substrate.

Abstract: A semiconductor device having a transistor or capacitor with an ultra-thin oxide, which is thinner than 10 angstrom in thickness, is manufactured by eliminating a gate oxidation step in the processing and using the polysilicon reoxidation step to create the ultra-thin gate oxide by diffusion after formation of the gate.

Abstract: A totally self-aligned transistor with shallow trench isolation. A single mask is used to align the source, drain, gate and isolation areas. Overlay error is greatly reduced by the use of a single mask for these regions. Channel dopant deposited in the gate area is also self-aligned to the gate of the transistor.

Abstract: A method for fabricating a MOSFET device is provided. The method includes a step of forming a gate oxide including first and second gate oxide materials. The first gate oxide material has a higher dielectric constant than the second gate oxide material. The first gate oxide material is formed to be over source/drain extension regions of the device; and the second gate oxide material is formed over a channel region of the device. The first gate oxide material has a low dielectric constant and provides for mitigating gate fringing field effects. The second gate oxide material has a high dielectric constant and provides for forming a thick gate oxide over a channel region of the device. Controlled uniform growth of the second gate oxide material is facilitated because of the thickness thereof.

Abstract: The present invention provides a fabrication process for fabricating a semiconductor integrated circuit device on a silicon substrate having an active device region isolated from the underlying substrate similar to a silicon on insulator(soi) substrate structure. The quasi-soi structure provides an inexpensive semiconductor integrated circuit device having a reduced floating body effect. The process for fabricating the substrate for use in fabricating the quasi-soi semiconductor device includes the steps of providing a silicon substrate member, fabricating at least one passivation layer consisting of silicon nitride over the silicon substrate member and protecting an underlying substrate surface region for subsequent fabrication of isolation trench regions, fabricating the isolation trench regions by etching portions of the passivation layer and portions of the substrate surface region forming an epitaxial silicon growing region.

Abstract: A self-aligned SOI device with body contact and silicide gate. The SOI device is formed using an ordinary substrate such as silicon. A silicide gate is self-aligned and formed from re-crystallization of nickel and amorphous silicon. The self-aligned silicide gate includes gate contact areas, and is self-aligned with respect to the gate opening, the source and drain regions and a nitride isolation layer. Nickel spacers deposited adjacent the isolation layer, and amorphous silicon deposited between the nickel spacers, form the self-aligned silicide gate through a silicidation process.

Abstract: A method for fabricating a MOSFET device is provided. The method includes a step of fining a gate oxide including first and second gate oxide materials. The first gate oxide material has a higher dielectric constant than the second gate oxide material. The first gate oxide material is formed to be over source/drain extension regions of the device; and the second gate oxide material is formed over a channel region of the device. The first gate oxide material has a low dielectric constant and provides for mitigating gate fringing field effects. The second gate oxide material has a high dielectric constant and provides for forming a thick gate oxide over a channel region of the device. Controlled uniform growth of the second gate oxide material is facilitated because of the thickness thereof.

Abstract: The present invention provides a method for forming a MOS device having self-compensating threshold adjust implants and reduced junction capacitance. A semiconductor substrate of a first conductivity type is provided. A gate oxide is formed on the surface of the semiconductor substrate, and a polysilicon gate is formed on the surface of the gate oxide. A first implant of a dopant of the first conductivity type is performed so as to form self-compensating implant regions in the semiconductor substrate on opposite sides of the gate. Disposable sidewall spacers are then formed around the polysilicon gate. A second implant of a dopant of a second conductivity type is performed so as to create highly-doped source/drain regions which are self-aligned to the sidewall spacers.

Abstract: A semiconductor apparatus formed on a semiconductor substrate includes a first active region in the substrate, and a second active region adjacent to the surface of the substrate separated from the first active region by a channel region. A gate oxide region may overlie at least a portion of the first and second active regions. The apparatus further includes a gate positioned over the channel region and having a first end and a second end respectively associated with the first and second active regions. The gate includes a first low conductive region and a second low conduction region at said first and second ends, respectively.A method for making the transistor structure of the present invention is also provided.

Abstract: A semiconductor apparatus formed on a semiconductor substrate includes a first active region in the substrate, and a second active region adjacent to the surface of the substrate separated from the first active region by a channel region. A gate oxide region may overlie at least a portion of the first and second active regions. The apparatus further includes a gate positioned over the channel region and having a first end and a second end respectively associated with the first and second active regions. The gate includes a first low conductive region and a second low conduction region at said first and second ends, respectively.A method for making the transistor structure of the present invention is also provided.

Abstract: An integrated semiconductor logic gate apparatus having optimized asymmetric channel regions and method for fabricating the apparatus is disclosed. The fabrication process includes ion-implanting the drain side of the channel to produce asymmetric channels on the gate transistors by using a criss-cross form of ion implantation. The criss-cross ion-implantation is performed after formation of the multiple gate stacks and is facilitated by a patterned photoresist mask that leaves an open, unprotected region above adjacent gate stacks through which the ion-implantation is performed. The criss-cross ion-implantation includes two tilt angles that are determined by tangent expressions that factor the height of the photoresist mask, the width of the unprotected opening over pairs of gate stacks and the width of the channel regions, including a distance relating to the point where the source/drain potential barrier is a minimum beneath the overlying gate stack.