Abstract:
A semiconductor structure includes an active region; a gate strip overlying the active region; and a metal-oxide-semiconductor (MOS) device. A portion of the gate strip forms a gate of the MOS device. A portion of the active region forms a source/drain region of the MOS device. The semiconductor structure further includes a stressor region over the MOS device; and a stressor-free region inside the stressor region and outside the region over the active region.
Abstract:
A method for forming masks for manufacturing a circuit includes providing a design of the circuit, wherein the circuit comprises a device; performing a first logic operation to determine a first region for forming a first feature of the device; and performing a second logic operation to expand the first feature to a second region greater than the first region. The pattern of the second region may be used to form the masks.
Abstract:
A method for forming both n and p wells in a semiconductor substrate using a single photolithography masking step, a non-conformal oxide layer and a chemical-mechanical polish step. A screen oxide layer is formed on a semiconductor substrate. A barrier layer is formed on the screen oxide layer. The barrier layer is patterned to form a first opening in the barrier layer over regions of the substrate where first wells will be formed. We implant impurities of a first conductivity type into the substrate to form first wells. In a key step, a non-conformal oxide layer is formed over the first well regions and the barrier layer. It is critical that the non-conformal oxide layer formed using a HDPCVD process. The non-conformal oxide layer is chemical-mechanical polished stopping at the barrier layer. The barrier layer is removed using a selective etch, to form second openings in the remaining non-conformal oxide layer over areas where second well will be formed in the substrate. Using the remaining non-conformal oxide as a mask, we implant impurities of the second conductivity type through the second openings to form second wells. The remaining non-conformal oxide layer and the screen oxide layer are removed.
Abstract:
A method to reduce to reduce DRAM capacitor STI junction leakage current. A Shallow Trench Isolation opening is formed, within this opening Field Oxide is deposited. The top surface of the FOX is etched down and a second layer of oxide is deposited over the FOX and the adjacent active regions. This second layer of oxide is etched bringing the top surface down to below the level of the top surface of the surrounding active areas but leaving spacers where the top surface of the FOX intersects with the active areas.
Abstract:
The active pixel cell structures and methods of preparing such structures described above enable reduction of dark current and white cell counts for active pixel cells. The process of preparing active pixel cell structures introduces stress on the substrate, which could lead to increased dark current and white cell counts of active pixel cells. By depositing a stress layer as part of a pre-metal dielectric layer with a stress that counters the stress induced, both the dark current and the white cell counts can be reduced. If the transistors of the active pixel cells are NMOS, the carrier mobility can also be increased by a tensile stress layer. Raman Spectroscopy can be used to measure the stress exerted on the substrate prior to the deposition of the stress layer.
Abstract:
A semiconductor device, such as a PMOS transistor, having localized stressors is provided. Recesses are formed on opposing sides of gate electrodes such that the recesses are offset from the gate electrode by dummy spacers. The recesses are filled with a stress-inducing layer. The dummy recesses are removed and lightly-doped drains are formed. Thereafter, new spacers are formed and the stress-inducing layer is recessed. One or more additional implants may be performed to complete source/drain regions. In an embodiment, the PMOS transistor may be formed on the same substrate as one or more NMOS transistors. Dual etch stop layers may also be formed over the PMOS and/or the NMOS transistors.
Abstract:
A method of manufacturing a plurality of MOS transistors includes forming gate structures in first and second regions on a substrate and forming mask portions only between adjacent drain sides of the respective gate structures only in the first region. Dopant of a first conductivity type that is the same as that of the substrate, is implanted at first and second angles in both the first and second regions to form halo regions only in source sides under the gate structures in the first region and in both source and drain sides under the gate structures in the second region.
Abstract:
A semiconductor device, such as a PMOS transistor, having localized stressors is provided. Recesses are formed on opposing sides of gate electrodes such that the recesses are offset from the gate electrode by dummy spacers. The recesses are filled with a stress-inducing layer. The dummy recesses are removed and lightly-doped drains are formed. Thereafter, new spacers are formed and the stress-inducing layer is recessed. One or more additional implants may be performed to complete source/drain regions. In an embodiment, the PMOS transistor may be formed on the same substrate as one or more NMOS transistors. Dual etch stop layers may also be formed over the PMOS and/or the NMOS transistors.
Abstract:
Methods and structures for CMOS devices with hybrid crystal orientations using double SOI substrates is provided. In accordance with preferred embodiments, a manufacturing sequence includes the steps of forming an SOI silicon epitaxy layer after the step of forming shallow trench isolation regions. The preferred sequence allows hybrid SOI CMOS fabrication without encountering problems caused by forming STI regions after epitaxy. A preferred device includes an NFET on a {100} crystal orientation and a PFET on a {110} crystal orientation. An NMOS channel may be oriented along the direction, which is the direction of maximum electron mobility for a {100} substrate. A PMOS channel may be oriented along the direction, which is the direction where hole mobility is maximum for a {110} substrate.
Abstract:
Disclosed herein are various embodiments of techniques for preventing silicide stringer or encroachment formation during metal salicide formation in semiconductor devices. The disclosed technique involves depositing a protective layer, such as a nitride or other dielectric layer, over areas of the semiconductor device where metal silicide formation is not desired because such formation detrimentally affects device performance. For example, silicon particles that may remain in device features that are formed through silicon oxidation, such as under the gate sidewall spacers and proximate to the perimeter of shallow trench isolation structures, are protected from reacting with metal deposited to form metal silicide in certain areas of the device. As a result, silicide stringers or encroachment in undesired areas is reduced or eliminated by the protective layer.