Abstract:
A reticle (130) provides an image pattern and compensates for a lens error in a photolithographic system. The reticle is structurally modified using image displacement data indicative of the lens error. The reticle can be structurally modified by adjusting the configuration (or layout) of radiation-transmitting regions (132, 134) for instance by adjusting a chrome pattern on the top surface of a quartz base. Alternatively, the reticle can be structurally modified by adjusting the curvature of the reticle, for instance by providing a chrome pattern on the top surface of a quartz base and grinding away portions of the bottom surface of the quartz base. The image displacement data may also vary as a function of lens heating so that the reticle compensates for lens heating associated with the reticle pattern.
Abstract:
A method of selectively exposing a material over a substrate is disclosed. The method includes forming a material over a semiconductor substrate, forming a photosensitive layer over the material, projecting a first image pattern onto the photosensitive layer that defines a first boundary for the material, projecting a second image pattern onto the photosensitive layer after projecting the first image pattern such that the second image pattern partially overlaps the first image pattern and defines a second boundary for the material, and removing portions of the photosensitive layer corresponding to the first and second image patterns. Preferably, the first and second image patterns are essentially identical to and laterally shifted with respect to one another. In this manner, the photosensitive layer selectively exposes the material adjacent to the first and second boundaries while covering the material between the first and second boundaries, and the distance between the first and second boundaries decreases as the overlap between the first and second image patterns decreases. Advantageously, the first and second boundaries can be closer than the minimum resolution of the photolithographic system used to pattern the photosensitive layer.
Abstract:
High-speed MOS transistors (32) are provided by forming a conductive layer (24) embedded in transistor gate sidewall spacers (27). The embedded conductive layer (24) is electrically insulated from the gate electrode (18) and the source/drain regions (28) of the transistor (32). The embedded conductive layer (24) is positioned over the source/drain extensions (30) and causes charge to accumulate in the source/drain extensions (30) lowering the series resistance of the source/drain regions (28).
Abstract:
Semiconductor devices with improved transistor performance are fabricated by forming a composite oxide/nitride liner (24,25) under a gate electrode sidewall spacer (40). Embodiements include depositing a conformal oxide layer (24) by decoupled plasma deposition, depositing a conformal nitride layer (25) by decoupled plasma deposition, depositing a spacer layer (30) and then etching.
Abstract:
A method of inspecting a lens (16) includes projecting a first amount of radiation through a first test pattern (42, 44) and the lens to provide a first lens error associated with a first heating of the lens, projecting a second amount of radiation through a second test pattern (52, 54) and the lens to provide a second lens error associated with a second heating of the lens, and using the first and second lens errors to provide image displacement data that varies as a function of heating the lens. In this manner, corrections can be made for localized lens heating that is unique to a given reticle. The method is well-suited for photolithographic systems such as step and repeat systems.
Abstract:
A method for fabrication of a non-symmetrical LDD-IGFET is described. In one embodiment, the method includes providing a semiconductor substrate having a gate insulator (104) and a gate electrode (106), the gate electrode having opposing first and second sidewalls (103, 105) defining the length of the gate electrode and a top surface. Lightly doped source (108) and drain (110) regions are implanted into the semiconductor substrate and are substantially aligned with the sidewalls of the gate electrode. After implanting the lightly doped regions, first and second spacers (112, 114) are formed adjacent to the first and second sidewalls of the gate electrode. After forming the spacers, a portion of the gate electrode is removed to form a third sidewall (117) of the gate electrode opposite the second sidewall (105), thereby eliminating the first sidewall and reducing the length of the gate electrode. After removing the first spacer, heavily doped source (120) and drain (118) regions are implanted into the semiconductor substrate. The heavily doped drain region is substantially aligned with the outer edge of the second spacer, a portion of the lightly doped drain regions is protected beneath the second spacer, and the heavily doped source region is substantially aligned with the third sidewall. In another embodiment, the heavily doped drain region is implanted after the spacers are formed but before the third sidewall is formed and the heavily doped source region is implanted after forming the third sidewall.
Abstract:
A method of forming a gate electrode for an insulated-gatefield-effectransistor (IGFET) is disclosed. The method includes forming a gate material for providing a gate electrode over a semiconductor substrate, forming a first mask over the gate material wherein the first mask includes an opening that defines a first edge of the gate electrode, removing a first portion of the gate material to form the first edge of the gate electrode as defined by the first mask, forming a second mask over the gate material after removing the first mask wherein the second mask includes an opening that defines a second edge of the gate electrode, removing a second portion of the gate material to form the second edge of the gate electrode as defined by the second mask, and removing the second mask. Thus, the gate electrode is defined by a lateral displacement between the openings in the first and second masks. Preferably, the first and second masks are photoresist, and the length between the first and second edges of the gate electrode is less than the minimum resolution of a photolithographic system used to pattern the masks.
Abstract:
A semiconductor device is provided with the high-speed capabilities of silicon on insulator (SOI) and strained silicon technologies, without requiring the formation of a silicon germanium layer. A layer of compressive material (22) is formed on a SOI semiconductor substrate (20) to induce strain in the overlying silicon layer (21). The compressive materials include silicon oxynitride, phosphorus, silicon nitride, and boron/phosphorus doped silica glass.
Abstract:
A method of making NMOS and PMOS devices with reduced masking steps is disclosed. The method includes providing a semiconductor substrate with a first active region of first conductivity type and a second active region of second conductivity type, forming a gate material over the first and second active regions, forming a first masking layer over the gate material, etching the gate material using the first masking layer as an etch mask to form a first gate over the first active region and a second gate over the second active region, implanting a dopant of second conductivity type into the first and second active regions using the first masking layer as an implant mask, forming a second masking layer that covers the first active region and includes an opening above the second active region, and implanting a dopant of first conductivity type into the second active region using the first and second masking layers as an implant mask. Advantageously, the dopant of first conductivity type counterdopes the dopant of second conductivity type in the second active region, thereby providing source and drain regions of second conductivity type in the first active region and source and drain regions of first conductivity type in the second active region with a single masking step and without subjecting either gate to dopants of first and second conductivity type.