Abstract:
A method of forming a region of impurity in a semiconductor substrate with minimal damage. The method includes the steps of: forming a reaction-inhibiting impurity region in the semiconductor substrate to a depth below the semiconductor substrate; and applying laser energy to the semiconductor substrate at a sufficient magnitude to liquify the semiconductor substrate in the region.
Abstract:
A dental adhesive containing an acidic group-containing radically polymerizable monomer, a non-acidic radically polymerizable monomer, a chemical polymerization initiator and a filler, as well as a 2,4-diphenyl-4-methyl-1-pentene. When the dental adhesive is used for adhering a crown restorative to the tooth, an excess of cement swelling from the surface of adhesion can be favorably removed, the curing time can be suitably adjusted without decreasing the strength of adhesion to the tooth, and a change in the color tone of the cured body can be effectively suppressed.
Abstract:
Submicron-dimensioned, MOSFET devices are formed using multiple implants for forming an impurity concentration distribution profile exhibiting three impurity concentration peaks at a predetermined depths below the semiconductor surface substrate. The inventive method reduces “latch-up” and “punch-through” with controllable adjustment of the threshold voltage.
Abstract:
Depletion of dopant from polysilicon gate layers with attendant dopant penetration of underlying gate oxide layers of silicon-based MOS and CMOS transistor devices are reduced or substantially eliminated by a process wherein a thin, high-quality silicon oxide gate insulator layer initially formed on a surface of a heavily-doped polysilicon substrate. The oxide layer is then subjected to impurity ion implantation selected to penetrate a desired depth into the underlying semiconductor substrate for formation of a structurally weakened cleavage plane thereat. The cleaved substrate is then bonded, via the silicon oxide gate insulator layer, to a second, lightly- to moderately-doped semiconductor substrate of similar conductivity type. The thus-produced composite is then subjected to further processing for patterning of the heavily-doped gate and gate insulator layers and to define active areas for formation of source/drain regions in the second, lightly-doped substrate.
Abstract:
Silicon-based, submicron-dimensioned MOS and/or CMOS transistor devices having substantially reduced source/drain junction-to-semiconductor substrate capacitance are formed by implanting oxygen atoms and/or molecules just below source/drain implant regions. Implantation conditions are selected to provide a peak oxygen implant concentration at a depth just below the ultimate source/drain junction depth. Subsequent thermal processing at elevated temperature results in source/drain dopant diffusion/activation and formation of a silicon oxide barrier layer or stratum just below the ultimate source/drain junction depth, thereby substantially reducing junction-to-substrate capacitance of refractory metal silicide-contact devices.
Abstract:
Submicron-dimensioned MOS and/or CMOS transistors are fabricated by a process employing removable sidewall spacers made of a material, such as UV-nitride, which has been treated subsequent to its deposition, e.g., by ion implantation, to augment its etch rate with a room temperature etchant, e.g., dilute aqueous HF. The treated spacers are removed with the dilute, aqueous HF after implantation of moderately or heavily-doped source/drain regions but prior to any post-implantation annealing processing, in order not to increase the etch resistance of the spacer material by thermally-induced densification.
Abstract:
Sub-micron-dimensioned, asymmetrically-configured MOS and/or CMOS transistors are fabricated using removable sidewall spacers made of a material, such as UV-nitride, one of which is selectively treated subsequent to deposition, e.g., by ion implantation, to augment the etch rate thereof with a room temperature etchant, e.g., dilute aqueous HF. The treated spacer is removed with the dilute, aqueous HF prior to implantation of asymmetrically-configured, moderately or heavily-doped source/drain regions but prior to any post-implantation annealing processing, in order not to increase the etch resistance of the spacer material by thermally-induced densification.
Abstract:
A semiconductor device with shallow junctions is obtained by forming shallow source/drain extensions followed by forming a film over the gate electrode and the semiconductor substrate. The film is formed having a targeted thicknesses to facilitate gate electrode doping and source/drain formation. Ion implantation is then conducted to fully dope the gate electrode and form moderately or heavily doped source/drain implants, thereby reducing gate depletion.
Abstract:
A process in accordance with the invention enables the manufacturability of raised source-drain MOSFETs. In accordance with the invention, a raised source-drain material, having a window therein, is formed over the substrate. A gate oxide and window sidewall oxides are subsequently formed. Dopants are diffused into the substrate. A gate is formed within the window.
Abstract:
A method of forming a titanium silicide (69) includes the steps of forming a transistor having a source region (58), a drain region (60) and a gate structure (56) and forming a titanium layer (66) over the transistor. A first anneal is performed with a laser anneal at an energy level that causes the titanium layer (66) to react with the gate structure (56) to form a high resistivity titanium silicide phase (68) having substantially small grain sizes. The unreacted portions of the titanium layer (66) are removed and a second anneal is performed, thereby causing the high resistivity titanium silicide phase (68) to convert to a low resistivity titanium silicide phase (69). The small grain sizes obtained by the first anneal allow low resistivity titanium silicide phase (69) to be achieved at device geometries less than about 0.25 micron.