Abstract: A method for forming a feature in a substrate, where residue within the feature can be easily removed. An upper sidewall portion of the feature is formed, where the upper sidewall portion forms a void in the substrate. The upper sidewall portion has an upper sidewall angle. A lower sidewall portion of the feature is formed, where the lower sidewall portion forms a void in the substrate. The lower sidewall portion has a lower sidewall angle. The upper sidewall angle of the upper sidewall portion is shallower than the lower sidewall angle of the lower sidewall portion. By forming the feature with a shallower sidewall angle at the top of the feature, any debris within the feature is more susceptible to rinsing, etching, or other cleaning procedures, and thus the feature is more easily cleaned than standard features having relatively steeper sidewalls.

Abstract: A method for forming a feature in a substrate, where residue within the feature can be easily removed. An upper sidewall portion of the feature is formed, where the upper sidewall portion forms a void in the substrate. The upper sidewall portion has an upper sidewall angle. A lower sidewall portion of the feature is formed, where the lower sidewall portion forms a void in the substrate. The lower sidewall portion has a lower sidewall angle. The upper sidewall angle of the upper sidewall portion is shallower than the lower sidewall angle of the lower sidewall portion. By forming the feature with a shallower sidewall angle at the top of the feature, any debris within the feature is more susceptible to rinsing, etching, or other cleaning procedures, and thus the feature is more easily cleaned than standard features having relatively steeper sidewalls.

Abstract: A wafer chuck is configured to hold a wafer efficiently for spin process cleaning of wafer edges and back sides. A first group of retractable tips extend to hold the wafer during a first portion of the cleaning period. A second group of retractable tips extend to hold the wafer during a second portion of the cleaning period. Residues left between the tips and the wafer edge areas during the first portion of the cleaning period are removed during the second portion. The change from the first group of tips to the second group of tips occurs while the wafer is rotating.

Abstract: A wafer chuck is configured to hold a wafer efficiently for spin process cleaning of wafer edges and back sides. A first group of retractable tips extend to hold the wafer during a first portion of the cleaning period. A second group of retractable tips extend to hold the wafer during a second portion of the cleaning period. Residues left between the tips and the wafer edge areas during the first portion of the cleaning period are removed during the second portion. The change from the first group of tips to the second group of tips occurs while the wafer is rotating.

Abstract: An anti-airlock apparatus for filters comprises a process bath for processing wafers, a filtration unit incorporating a filter for preliminarily filtering a process solution before said processing and connected to a first deaeration line, and a tank body provided on the primary side or the filtration unit and connected to a second deaeration line, wherein at least said filtration unit and tank body are connected to each other via a pipeline, and a valve of the first deaeration line and a valve of the second deaeration line are separately operated and said first and second deaeration lines are directly connected to the most upstream side of the process solution.

Abstract: The present invention prevents deposition on product wafers of microbubbles generated from chemical solution circulation systems for wet etching or wet cleaning, or pure water supply systems during manufacturing processes of semiconductors or liquid crystals. A separator is provided on the inner wall of a chemical solution bath for etching or cleaning wafers to cover a process solution nozzle. The separator comprises an upper microbubble discharge tube extending upright for discharging microbubbles and lower outlets for horizontally introducing a process solution into the process bath.

Abstract: A method of removing particles adhering to a surface of a semiconductor wafer including the steps of: providing a container having a drain valve; positioning the semiconductor wafer in the container; directing a jet stream consisting of water against the surface of the semiconductor wafer; removing particles adhering to the surface of the semiconductor wafer by scrubbing the surface of the semiconductor wafer with a brush while the jet stream of water is directed against the surface of the semiconductor wafer; closing the drain valve while the jet stream of water is directed against the semiconductor wafer, wherein the water accumulates in the container to thereby completely immerse the brush and the semiconductor wafer in the water in the container; and maintaining the brush and the semiconductor wafer completely immersed in the water from the jet stream for a predetermined period of time.

Abstract: An object of the present invention is to prevent erroneous operation of a liquid level sensor due to deposition of ammonium fluoride dissolved in buffered hydrofluoric acid used as a process solution.The present invention provides a liquid level sensor comprising a chemical solution bath for receiving a chemical solution including buffered hydrofluoric acid, a gas feed tube for introducing a gas for detecting the variation in the liquid level of said chemical solution into said chemical solution, and a gas pressure detector for detecting a change in the pressure of said gas and converting it into an electric signal to indicate a change in liquid level, characterized in that the diameter of a gas outlet provided at an end of said gas feed tube is smaller than the inner diameter of said gas feed tube.

Abstract: Herein disclosed is a filter medium for molten metals which consists of a sintered body of a mixture comprising 100 parts by weight of at least one refractory grain selected from the group consisting of alumina particles and Al.sub.2 O.sub.3.MgO spinel crystal particles; and 5 to 25 parts by weight of an inorganic binder which comprises 60 to 90% by weight of Al.sub.2 O.sub.3.MgO spinel crystal powder, 5 to 12% by weight of B.sub.2 O.sub.3, and not more than 30% by weight of at least one oxide selected from the group consisting of Al.sub.2 O.sub.3, MgO and TiO.sub.2. The filter medium is used for filtering off solid impurities mixed in molten metals, in particular, molten aluminums.