Abstract:
A shallow doped junction that is part of an integrated circuit device within a semiconductor substrate is formed with box-shaped implant profiles for implantation of the amorphizing implant species and the dopant implant species such that the doped junction has minimized sheet resistance. A box-shaped implant profile for implantation of the amorphizing implant species is formed from implantation of the amorphizing implant species with a plurality of projection ranges to form a plurality of implant profiles. A box-shaped implant profile for implantation of the dopant implant species is formed from implantation of the dopant implant species with a plurality of projection ranges to form a plurality of implant profiles. In addition, each of the plurality of implant profiles for the dopant implant species is preferably below the solid solubility of the dopant implant species within the semiconductor substrate. By controlling the implant profiles of the amorphizing implant species and the dopant implant species during fabrication of the doped junction, the sheet resistance of the doped junction is minimized. In addition, the temperature and the time period for activating the dopant implant species in a RTA (Rapid Thermal Anneal) process is also minimized such that the doped junction remains relatively shallow.
Abstract:
A field effect transistor (FET) is formed on a silicon substrate, with a nitride gate insulator layer being deposited on the substrate and an oxide gate insulator layer being deposited on the nitride layer to insulate a gate electrode from source and drain regions in the substrate. The gate material is then removed to establish a gate void, and spacers are deposited on the sides of the void such that only a portion of the oxide layer is covered by the spacers. Then, the unshielded portion of the oxide layer is removed, thus establishing a step between the oxide and nitride layers that overlays the source and drain extensions under the gate void to reduce subsequent capacitive coupling and charge carrier tunneling between the gate and the extensions. The spacers are removed and the gate void is refilled with gate electrode material.
Abstract:
A method of fabricating an integrated circuit with ultra-shallow source and drain junctions utilizes a damascene process. The substrate is over-etched to form extensions in the source and drain regions. The process can be utilized for P-channel or N-channel metal oxide field semiconductor effect transistors (MOSFETS).
Abstract:
An ultra-large scale integrated (ULSI) circuit includes MOSFETs which have different threshold voltages and yet have the same channel characteristics. The MOSFETs utilize gate structures with heavily doped polysilicon and germanium material. The polysilicon and germanium materials or thin films are manufactured by low pressure chemical vapor deposition. A silicon buffer layer and oxide cap is used to prevent germanium outgassing.
Abstract:
A coupling capacitor is coupled between the gate and the body region of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The body region of the MOSFET is electrically isolated to form a floating body region. The capacitance of the coupling capacitor is designed such that a BJT (Bipolar Junction Transistor) connected in parallel with the MOSFET turns on when the MOSFET turns on. In addition such a design of the coupling capacitor lowers the magnitude of the threshold voltage of the MOSFET when the MOSFET is turned on. Furthermore, the capacitance of the coupling capacitor is designed such that the magnitude of the threshold voltage of the MOSFET is raised when the MOSFET is turned off. Thus, the MOSFET type device of the present invention has both higher drive current when the MOSFET is turned on and lower steady state power dissipation when the MOSFET is turned off with a variable threshold voltage.
Abstract:
A method of performing tilted implantation for pocket, halo and source/drain extensions in ULSI dense structures. The method overcomes the process limit, due to shadowing effects, in dense structures, of using large angle tilted implant techniques in ULSI circuits. A gate opening in an oxide layer is defined and partially filled by insertion of nitride spacers to define an actual gate window opening. The small angle tilted implant technique has the equivalent doping effect of large angle tilted implants, and circumvents the maximum angle limit (&thgr;MAX) that occurs in the large angle implant method. The small angle tilted implant technique also automatically provides self alignment of the pocket/halo/extension implant to the gate of the device.
Abstract:
An ultra-large-scale integrated (ULSI) circuit includes MOSFETs which have different threshold voltages and yet have the same channel characteristics. The MOSFETs are provided on an SOI substrate. The thickness of a thin film on the substrate is varied to adjust the threshold voltage. The threshold voltage can be varied by roughly 240 mV. The thickness of the thin film can be adjusted through a LOCOS process.
Abstract:
A method of fabricating an integrated circuit with ultra-shallow source and drain junctions utilizes a dummy or sacrificial gate spacer. Ions are implanted and dopants are provided through the openings associated with sacrificial spacers to form the source and drain extensions. The openings can be filled with an insulative layer. The process can be utilized for P-channel or N-channel metal oxide semiconductor field effect transistors (MOSFETS).
Abstract:
An ultra-low thermal budget process is provided for channel implant by using a reverse process sequence where a conventional MOS transistor is formed without the channel implant. The originally deposited polysilicon gate is removed, a nitride film deposition and etch is used to form a nitride spacer with a predetermined configuration, and a self-aligned channel implant is performed. After the channel implantation, anneal and super-retrograded doping, the nitride spacer and the gate oxide are removed for subsequent regrowth of a second gate oxide and a polysilicon deposition to form a second polysilicon gate.
Abstract:
A method for making a ULSI MOSFET includes establishing a void in a field oxide layer on a silicon substrate and filling the center of the void with a gate electrode. A high-k gate insulator is sandwiched between the gate electrode and the substrate. Around the void, a low-k gate spacer is formed, with the gate spacer being disposed directly above the source and drain extensions of the MOSFET.