摘要:
Vertical device structures incorporating at least one nanotube and methods for fabricating such device structures by chemical vapor deposition. Each nanotube is grown by chemical vapor deposition catalyzed by a catalyst pad and encased in a coating of a dielectric material. Vertical field effect transistors may be fashioned by forming a gate electrode about the encased nanotubes such that the encased nanotubes extend vertically through the thickness of the gate electrode. Capacitors may be fashioned in which the encased nanotubes and the corresponding catalyst pad bearing the encased nanotubes forms one capacitor plate.
摘要:
A field effect transistor is formed having wrap-around, vertically-aligned, dual gate electrodes. Starting with a silicon-on-insulator (SOI) structure having a buried silicon island, a vertical reference edge is defined, by creating a cavity within the SOI structure, and used during two etch-back steps that can be reliably performed. The first etch-back removes a portion of an oxide layer for a first distance over which a gate conductor material is then applied. The second etch-back removes a portion of the gate conductor material for a second distance. The difference between the first and second distances defines the gate length of the eventual device. After stripping away the oxide layers, a vertical gate electrode is revealed that surrounds the buried silicon island on all four side surfaces.
摘要:
To isolate two active regions formed on a silicon-on-insulator (SOI) substrate, a shallow trench isolation region is filled with liquid phase deposited silicon dioxide (LPD-SiO2) while avoiding covering the active areas with the oxide. By selectively depositing the oxide in this manner, the polishing needed to planarize the wafer is significantly reduced as compared to a chemical-vapor deposited oxide layer that covers the entire wafer surface. Additionally, the LPD-SiO2 does not include the growth seams that CVD silicon dioxide does. Accordingly, the etch rate of the LPD-SiO2 is uniform across its entire expanse thereby preventing cavities and other etching irregularities present in prior art shallow trench isolation regions in which the etch rate of growth seams exceeds that of the other oxide areas.
摘要:
Vertical field effect transistors having a channel region defined by at least one semiconducting nanotube and methods for fabricating such vertical field effect transistors by chemical vapor deposition using a spacer-defined channel. Each nanotube is grown by chemical vapor deposition catalyzed by a catalyst pad positioned at the base of a high-aspect-ratio passage defined between a spacer and a gate electrode. Each nanotube grows in the passage with a vertical orientation constrained by the confining presence of the spacer. A gap may be provided in the base of the spacer remote from the mouth of the passage. Reactants flowing through the gap to the catalyst pad participate in nanotube growth.
摘要:
Vertical field effect transistors having a channel region defined by at least one semiconducting nanotube and methods for fabricating such vertical field effect transistors by chemical vapor deposition using a spacer-defined channel. Each nanotube is grown by chemical vapor deposition catalyzed by a catalyst pad positioned at the base of a high-aspect-ratio passage defined between a spacer and a gate electrode. Each nanotube grows in the passage with a vertical orientation constrained by the confining presence of the spacer. A gap may be provided in the base of the spacer remote from the mouth of the passage. Reactants flowing through the gap to the catalyst pad participate in nanotube growth.
摘要:
Methods for synthesizing carbon nanotubes and structures formed thereby. The method includes forming carbon nanotubes on a plurality of synthesis sites supported by a first substrate, interrupting nanotube synthesis, mounting a free end of each carbon nanotube to a second substrate, and removing the first substrate. Each carbon nanotube is capped by one of the synthesis sites, to which growth reactants have ready access. As the carbon nanotubes lengthen during resumed nanotube synthesis, access to the synthesis sites remains unoccluded.
摘要:
The invention provides a method of forming a phase shift mask and the resulting phase shift mask. The method forms a non-transparent film on a transparent substrate and patterns an etch stop layer on the non-transparent film. The invention patterns the non-transparent film using the etch stop layer to expose areas of the transparent substrate. Next, the invention forms a mask on the non-transparent film to protect selected areas of the transparent substrate and forms a phase shift oxide on exposed areas of the transparent substrate. Subsequently, the mask is removed and the phase shift oxide is polished down to the etch stop layer, after which the etch stop layer is removed.
摘要:
An immersion lithography apparatus and method, and a lithographic optical column structure are disclosed for conducting immersion lithography with at least the projection optics of the optical system and the wafer in different fluids at the same pressure. In particular, an immersion lithography apparatus is provided in which a supercritical fluid is introduced about the wafer, and another fluid, e.g., an inert gas, is introduced to at least the projection optics of the optical system at the same pressure to alleviate the need for a special lens. In addition, the invention includes an immersion lithography apparatus including a chamber filled with a supercritical immersion fluid and enclosing a wafer to be exposed and at least a projection optic component of the optical system.
摘要:
A liquid-filled balloon may be positioned between a workpiece, such as a semiconductor structure covered with a photoresist, and a lithography light source. The balloon includes a thin membrane that exhibits good optical and physical properties. Liquid contained in the balloon also exhibits good optical properties, including a refractive index higher than that of air. Light from the lithography light source passes through a mask, through a top layer of the balloon membrane, through the contained liquid, through a bottom layer of the balloon membrane, and onto the workpiece where it alters portions of the photoresist. As the liquid has a low absorption and a higher refractive index than air, the liquid-filled balloon system enhances resolution. Thus, the balloon provides optical benefits of liquid immersion without the complications of maintaining a liquid between (and in contact with) a lithographic light source mechanism and workpiece.
摘要:
An immersion lithography apparatus and method, and a lithographic optical column structure are disclosed for conducting immersion lithography with at least the projection optics of the optical system and the wafer in different fluids at the same pressure. In particular, an immersion lithography apparatus is provided in which a supercritical fluid is introduced about the wafer, and another fluid, e.g., an inert gas, is introduced to at least the projection optics of the optical system at the same pressure to alleviate the need for a special lens. In addition, the invention includes an immersion lithography apparatus including a chamber filled with a supercritical immersion fluid and enclosing a wafer to be exposed and at least a projection optic component of the optical system.