Abstract: Provided are a method and an apparatus for a handoff decision in a mobile communication system. The method includes comparing a threshold value with a measured Received Signal Strength (RSS) of a serving base station, and if the threshold value is greater than the measured RSS, operating a handoff timer; calculating an approximate RSS using the RSS, which has experienced a forward link power control, and a handoff weight, and comparing the threshold value with the approximate RSS. If the approximate RSS is less than the threshold value, a handoff is performed. Thus, an accurate channel state is considered to determine whether to handoff.

Abstract: A method for fabricating a cell transistor of a flash memory including a device isolation film is disclosed, to prevent the mouse bite and the residue of a gate electrode, which includes the steps of forming a moat pattern of STI structure on a semiconductor substrate; forming a shallow trench by etching the semiconductor substrate exposed by the moat pattern; forming a gap-fill insulating layer in the shallow trench by HDP; forming the device isolation film of STI structure in the shallow trench by etching the gap-fill insulating layer with CMP; forming a flash cell pattern for opening an area for flash memory cell transistor in the semiconductor substrate; and removing the flash cell pattern and the moat pattern after etching the upper surface of the device isolation film in the area being opened by the flash cell pattern.

Abstract: An apparatus for cleaning semiconductor wafers includes a chamber, a bubbler having a vapor generating part for generating alcohol vapor and a spray pipe for spraying the alcohol vapor into the chamber, a gas supply nozzle for spraying gas into the chamber to dry the wafers, a liquid supply nozzle for supplying cleaning liquid into the chamber and a discharge system. The spray pipe of the bubbler has a liquid retention portion that keeps condensate of the alcohol vapor from issuing into the chamber. The gas supply nozzle has a spray outlet configured to spray the same amount of the drying gas onto all of the wafers in the chamber. The liquid supply nozzle has liquid supply openings only in a side portion thereof so that liquid alcohol will not become trapped therein.

Abstract: The present invention relates to an electrostatic chuck having electrodes of which polarities are periodically inverted, and a method for chucking wafers using the electrostatic chuck. The electrostatic chuck of the present invention includes an electrode part including first and second electrodes having different polarities and generating electrostatic charge for fixing a wafer, an electric source part having a first electric source for supplying positive and negative electricity to the respective first and second electrodes and a second electric source for supplying the negative and positive electricity to the respective first and second electrodes, and a polarity inversion part for inverting the polarities of the first and second electrodes every cycle.

Abstract: A cleaning solution for use in removing a damaged portion of a ferroelectric layer, and a cleaning method using the solution. The cleaning solution includes a fluoride, an organic acid with carboxyl group, an alkaline pH adjusting agent and water.

Abstract: A wafer drying method includes submerging a wafer in a cleaning solution in a dry chamber. An organic liquid vapor from an organic liquid is supplied into the dry chamber at a first volumetric supply rate to form an organic liquid layer on a surface of the cleaning solution, the organic liquid layer having at least a prescribed concentration of the organic liquid. The organic liquid vapor is supplied into the dry chamber at a second volumetric supply rate that is lower than the first volumetric supply rate. During and/or following the supplying of the organic liquid vapor into the dry chamber, at least a portion of the wafer is removed from the cleaning solution through the organic liquid layer.

Abstract: Disclosed is a high density plasma apparatus, which is capable of preventing breakage of an insulation film due to a potential difference by removing the potential difference in the course of transferring a wafer from a process chamber to a transfer chamber after completing a plasma process. The high density plasma apparatus may include a transfer chamber including a wafer transfer robot; a process chamber connected to the transfer chamber for plasma-processing a wafer being transferred by the wafer transfer robot; and an ultraviolet irradiator provided in the transfer chamber for irradiating an ultraviolet ray on the wafer plasma-processed in the process chamber and being transferred to the transfer chamber.

Abstract: A wafer drying method includes submerging a wafer in a cleaning solution in a dry chamber. An organic liquid vapor from an organic liquid is supplied into the dry chamber at a first volumetric supply rate to form an organic liquid layer on a surface of the cleaning solution, the organic liquid layer having at least a prescribed concentration of the organic liquid. The organic liquid vapor is supplied into the dry chamber at a second volumetric supply rate that is lower than the first volumetric supply rate. During and/or following the supplying of the organic liquid vapor into the dry chamber, at least a portion of the wafer is removed from the cleaning solution through the organic liquid layer.

Abstract: A semiconductor device and fabrication method thereof that uses a far ultraviolet ray photolithography, which may be used to prevent the lift phenomenon of a photoresist pattern, is disclosed. The semiconductor device may be fabricated by the process of: forming a film which is an object of forming a pattern on a structure of a semiconductor substrate; forming a anti-reflection layer on the film to form a stacking structure including the film and the anti-reflection layer; performing a plasma treatment to form grooves on a upper surface of the stacking structure; forming a photoresist pattern on the stacking structure on which the grooves are formed; and etching the stacking structure using the photoresist pattern as a mask to form a stacking structure pattern.

Abstract: The present invention relates to an electrostatic chuck having electrodes of which polarities are periodically inverted, and a method for chucking wafers using the electrostatic chuck. The electrostatic chuck of the present invention includes an electrode part including first and second electrodes having different polarities and generating electrostatic charge for fixing a wafer, an electric source part having a first electric source for supplying positive and negative electricity to the respective first and second electrodes and a second electric source for supplying the negative and positive electricity to the respective first and second electrodes, and a polarity inversion part for inverting the polarities of the first and second electrodes every cycle.

Abstract: A semiconductor device and fabrication method thereof that uses a far ultraviolet ray photolithography, which may be used to prevent the lift phenomenon of a photoresist pattern, is disclosed. The semiconductor device may be fabricated by the process of: forming a film which is an object of forming a pattern on a structure of a semiconductor substrate; forming a anti-reflection layer on the film to form a stacking structure including the film and the anti-reflection layer; performing a plasma treatment to form grooves on a upper surface of the stacking structure; forming a photoresist pattern on the stacking structure on which the grooves are formed; and etching the stacking structure using the photoresist pattern as a mask to form a stacking structure pattern.

Abstract: Methods of forming a gap filling layer using high density plasma are disclosed.

Abstract: A semiconductor device and fabrication method thereof that uses a far ultraviolet ray photolithography, which may be used to prevent the lift phenomenon of a photoresist pattern, is disclosed. The semiconductor device may be fabricated by the process of: forming a film which is an object of forming a pattern on a structure of a semiconductor substrate; forming a anti-reflection layer on the film to form a stacking structure including the film and the anti-reflection layer; performing a plasma treatment to form grooves on a upper surface of the stacking structure; forming a photoresist pattern on the stacking structure on which the grooves are formed; and etching the stacking structure using the photoresist pattern as a mask to form a stacking structure pattern.

Abstract: A cleaning solution for use in removing a damaged portion of a ferroelectric layer, and a cleaning method using the solution. The cleaning solution includes a fluoride, an organic acid with carboxyl group, an alkaline pH adjusting agent and water.

Abstract: A semiconductor device and fabrication method thereof that uses a far ultraviolet ray photolithography, which may be used to prevent the lift phenomenon of a photoresist pattern, is disclosed. The semiconductor device may be fabricated by the process of: forming a film which is an object of forming a pattern on a structure of a semiconductor substrate; forming a anti-reflection layer on the film to form a stacking structure including the film and the anti-reflection layer; performing a plasma treatment to form grooves on a upper surface of the stacking structure; forming a photoresist pattern on the stacking structure on which the grooves are formed; and etching the stacking structure using the photoresist pattern as a mask to form a stacking structure pattern.

Abstract: A method of forming a shallow trench isolation type semiconductor device comprises forming an etch protecting layer pattern to define at least one active region on a substrate, forming at least one trench by etching the substrate partially by using the etch protecting layer pattern as an etch mask, forming a thermal-oxide film on an inner wall of the trench, filling the trench having the thermal-oxide film with a CVD silicon oxide layer to form an isolation layer, removing the etch protecting layer pattern from the substrate over which the isolation layer is formed, removing the thermal-oxide film formed on a top end of the inner wall of the trench to a depth of 100 to 350 Å, preferably 200 Å from the upper surface of the substrate, and forming a gate oxide film on the substrate from which the active region and the top end are exposed.

Abstract: An apparatus for cleaning semiconductor wafers includes a chamber, a bubbler having a vapor generating part for generating alcohol vapor and a spray pipe for spraying the alcohol vapor into the chamber, a gas supply nozzle for spraying gas into the chamber to dry the wafers, a liquid supply nozzle for supplying cleaning liquid into the chamber and a discharge system. The spray pipe of the bubbler has a liquid retention portion that keeps condensate of the alcohol vapor from issuing into the chamber. The gas supply nozzle has a spray outlet configured to spray the same amount of the drying gas onto all of the wafers in the chamber. The liquid supply nozzle has liquid supply openings only in a side portion thereof so that liquid alcohol will not become trapped therein.

Abstract: A pre-stripping treatment solution for treatment of metal surfaces before stripping photoresist which has been used for patterning a metal layer. Also provided is a method of removing the photoresist, and a method of manufacturing semiconductor devices using the above solution and method. In one aspect of the invention, the photoresist is first ashed. The ashed resultant structure is then treated, prior to stripping of the photoresist, with a pre-stripping treatment solution of an organic acid solution having a carboxyl group is mixed with deionized water at a volume ratio of 1:0 to 1:100.

Abstract: A wet process performed in the manufacture of semiconductor devices with cathode water and anode water produced from electrolyte using a 3-cell electrolyzer having an intermediate cell for the electrolyte. The 3-cell electrolyzer includes an anode cell, a cathode cell, and an intermediate cell between the anode and cathode cells, which are partitioned by ion exchange membranes. Deionized water is supplied into the anode and cathode cells, and the intermediate cell is filled with an electrolytic aqueous solution to perform electrolysis. The anode water containing oxidative substances or the cathode water containing reductive substances, which are produced by the electrolysis process, are used in the wet process.

Abstract: A method of manufacturing a semiconductor device having a hemispherical grain (HSG) layer employs a dry cleaning process. A polysilicon layer is formed on a specific material layer on a semiconductor substrate. Next, a polysilicon pattern, at least a portion of which is exposed, is formed by etching the polysilicon layer. The exposed surface of the polysilicon pattern is then dry cleaned by supplying hydrogen in a plasma state and a fluorine-based gas toward the exposed surface. The exposed surface of the polysilicon pattern may also be wet cleaned before being dry cleaned to wash away pollutants which may have been left thereon. An HSG layer is then formed on the cleaned surface of the polysilicon pattern. After the HSG layer is formed, the surface of the HSG layer may be dry cleaned again by supplying hydrogen in a plasma state and a fluorine-based gas toward the surface of the HSG layer. The surface of the HSG layer may also be further wet cleaned before being dry cleaned.