Abstract: A method for fabricating a dual gate structure, comprising providing a semiconductor substrate having a first device area and a second device area covered by a gate oxide layer and a polysilicon layer, forming a first hard mask over the polysilicon layer, said first hard mask being a material that is resistant to a first etching, but susceptible to a second etching forming a second hard mask over the first hard mask and the polysilicon layer, said second hard mask being a material that is resistant to a second etching, but susceptible to a first etching, patterning and etching said second hard mask with a first etch to form a gate pattern on a first device area, and patterning and etching said first hard mask with a second etch to transfer gate patterns on the first and second device areas.

Abstract: A method for fabricating a dual gate structure, comprising providing a semiconductor substrate having a first device area and a second device area covered by a gate oxide layer and a polysilicon layer, forming a first hard mask over the polysilicon layer, said first hard mask being a material that is resistant to a first etching, but susceptible to a second etching forming a second hard mask over the first hard mask and the polysilicon layer, said second hard mask being a material that is resistant to a second etching, but susceptible to a first etching, patterning and etching said second hard mask with a first etch to form a gate pattern on a first device area, and patterning and etching said first hard mask with a second etch to transfer gate patterns on the first and second device areas.

Abstract: A pair of transistors sharing a common electrodes e.g. a bitline in a DRAM array, has a self-aligned contact to the bitline in which the transistor gate stack has only a poly layer with a nitride cover; the aperture for the bitline contact is time-etched to penetrate only between the gates and not reach the silicon substrate; exposed nitride shoulders of the gate are etched to expose the poly; the remainder of the interlayer dielectric is removed by a selective etch; the exposed poly is re-oxidized to protect the gates; and the aperture bottom is cleaned; so that the thick gate stack of a DRAM is dispensed with in order to improve uniformity of line width across the chip beyond what the DRAM technique can deliver.

Abstract: A method for the removal of fluorine or chlorine residue from an etched precision surface such as a semiconductor sample is provided which comprises exposing said precision surface to liquid CO.sub.2 under appropriate conditions that are sufficient to remove the residue from the precision surface. Cryogenic aerosol may be used in conjunction with liquid CO.sub.2.

Abstract: A method for the removal of residue from an etched precision surface such as a semiconductor sample is provided which comprises exposing said precision surface to a supercritical fluid or liquid CO.sub.2 under appropriate conditions that are sufficient to remove the residue from the precision surface. Cryogenic aerosol may be used in conjunction with either the supercritical fluid or liquid CO.sub.2.

Abstract: A vapor drying system includes a tank for holding a drying liquid and a heater for boiling the drying liquid in the tank to produce a vapor. A manifold is arranged in the tank for bubbling gas into the drying liquid. A controller is configured to cause the manifold to bubble gas into the drying liquid at a time when substrates to be dried are first introduced into the tank in order to quench the boiling of the drying liquid and generate a saturated vapor at a rate sufficient to achieve condensation of the drying liquid over substantially the entire surface of each of the substrates to be dried. In this way, staining of the substrates is reduced and process yield is improved.

Abstract: A film layer not susceptible to aerosol cleaning is removed from a surface by converting the film layer into a film susceptible to aerosol cleaning, and aerosol jet cleaning the converted film and any contaminants. The aerosol jet can be moved in relation to the surface to provide thorough cleaning.

Abstract: A cryogenic aerosol separator/classifier for separating and selectively removing particles from a stream of aerosol. The aerosol stream is produced by a cryogenic aerosol generator comprising a reservoir containing a cryogenic gas-liquid mixture at a first pressure, a delivery line coupled to the reservoir, and a nozzle. The nozzle has at least one exit opening which allows the cryogenic gas-liquid mixture to expand from the first pressure to a lower pressure and, thus, to produce cryogenic aerosol. A separator is coupled to the nozzle, such that the light particles having high mobility are removed from the stream, thereby producing a stream of cryogenic flow with particles having a controlled size to clean a contaminated surface. The apparatus is enhanced by utilizing a magnetic field and/or specially designed flow fields to fully take advantage of the enhanced mobilities of light particles.