Abstract: To provide a method for producing an aluminum ingot whose oxides is reduced by preventing the surface of molten aluminum from being oxidized. The method according to the present invention includes a melting step (melting furnace 1) of melting an aluminum base metal into a molten aluminum or molten aluminum alloy; a holding step (holding furnace 2) of holding the resulting molten aluminum or molten aluminum alloy; a dehydrogenation step (dehydrogenation unit 3) of removing hydrogen gas from the molten aluminum or molten aluminum alloy; a filtration step (filter 4) of removing inclusions from the molten aluminum or molten aluminum alloy; and a casting step (casting device 5) of solidifying the molten aluminum or molten aluminum alloy into a predetermined shape, wherein at least one of the above steps is conducted in the atmosphere of a protective gas containing fluorinating gas, carbon dioxide gas, and nitrogen and/or argon gas.

Abstract: A semiconductor device manufacturing method includes: a step of implementing etching onto a film formed on a semiconductor wafer; and a removal step of supplying, after etching, a removing solution for removing deposition on the film to a semiconductor wafer in the state where the number of rotations thereof is smaller than a predetermined number of rotations thereafter to rotate the semiconductor wafer at a higher number of rotations, which is greater than the predetermined number of rotations. In this method, the time during which removing solution is supplied is 45 sec. or less. This method includes a sequence in which removal step is executed twice or more.

Abstract: The invention provides an internal filter with an improved filtering ability of removing particularly fine inclusion particles from molten aluminum or molten aluminum alloy. The internal filter includes an aggregate meshed member made of a refractory material and a coating layer formed on a surface of the aggregate meshed member. The coating layer contains a soda silicate that is able to be softened or viscous at a temperature of the molten aluminum alloy.

Abstract: A reactor of a chemical vapor deposition system is equipped with a gas feeder for blowing dopant gas to plural semiconductor wafers supported by a wafer boat at intervals, and the gas feeder has a gas passage gradually reduced in cross section and gas outlet holes equal in diameter and arranged along the wafer boat for keeping the doping gas concentration substantially constant around the semiconductor wafers, whereby the dopant is uniformly introduced in material deposited on all the semiconductor wafers.

Abstract: The invention provides an internal filter with an improved filtering ability of removing particularly fine inclusion particles from molten aluminum or molten aluminum alloy. The internal filter includes an aggregate meshed member made of a refractory material and a coating layer formed on a surface of the aggregate meshed member. The coating layer contains a soda silicate that is able to be softened or viscous at a temperature of the molten aluminum alloy.

Abstract: A reactor of a chemical vapor deposition system is equipped with a gas feeder for blowing dopant gas to plural semiconductor wafers supported by a wafer boat at intervals, and the gas feeder has a gas passage gradually reduced in cross section and gas outlet holes equal in diameter and arranged along the wafer boat for keeping the doping gas concentration substantially constant around the semiconductor wafers, whereby the dopant is uniformly introduced in material deposited on all the semiconductor wafers.