Abstract: A method for preparing a photomask blank comprising a transparent substrate and a chromium-containing film contiguous thereto involves the step of depositing the chromium-containing film by sputtering a metallic chromium target having an Ag content of up to 1 ppm. When a photomask prepared from the photomask blank is repeatedly used in patternwise exposure to ArF excimer laser radiation, the number of defects formed on the photomask is minimized.

Abstract: A method for preparing a photomask blank comprising a transparent substrate and a chromium-containing film contiguous thereto involves the step of depositing the chromium-containing film by sputtering a metallic chromium target having an Ag content of up to 1 ppm. When a photomask prepared from the photomask blank is repeatedly used in patternwise exposure to ArF excimer laser radiation, the number of defects formed on the photomask is minimized.

Abstract: A quadrupole mass spectrometer for use in analyzing gas components in a test piece is made in a constitution in which resistance heating of a grid is materialized, and in which a high-accuracy analysis of the gas components is possible at a low cost while preventing the sensitivity from lowering. A quadrupole mass spectrometer is provided with a sensor section which can be detachably fitted to the test piece.

Abstract: A quadrupole mass spectrometer for use in analyzing gas components in a test piece is made in a constitution in which resistance heating of a grid is materialized, and in which a high-accuracy analysis of the gas components is possible at a low cost while preventing the sensitivity from lowering. A quadrupole mass spectrometer is provided with a sensor section which can be detachably fitted to the test piece.

Abstract: A mass spectrometry unit of the present invention includes a mass spectrometry portion that detects ion current values of a gas to be measured according to mass-to-charge ratio, to thereby measure partial pressures of the gas to be measured. The mass spectrometry unit further includes: a control portion for preliminary storing a record of a mass-to-charge ratio of a specific gas that decreases a function of a specific portion of the mass spectrometry unit, in which if an ion current value with the mass-to-charge ratio of the specific gas detected by the mass spectrometry portion is not less than a predetermined value, the control portion outputs a warning signal denoting a functional decrease in the specific portion.

Abstract: A method of controlling a mass spectrometer comprises the steps of: supplying a current to a cathode electrode of an ion source having the cathode electrode and an anode electrode, and ionizing a molecules of a gas to be measured; selecting ions generated in the ion source by mass-to-charge ratio; and detecting an ion current value of the selected ions. When a partial pressure of the gas to be measured is measured based on a detection result of the ion current value, a cathode current is supplied to the cathode electrode such that an emission current flowing between the cathode electrode and the anode electrode becomes constant. When a partial pressure of the gas to be measured is not measured, a constant current having a current value less than that of the cathode current is supplied to the cathode electrode.

Abstract: A method of controlling a mass spectrometer comprises the steps of: supplying a current to a cathode electrode of an ion source having the cathode electrode and an anode electrode, and ionizing a molecules of a gas to be measured; selecting ions generated in the ion source by mass-to-charge ratio; and detecting an ion current value of the selected ions. When a partial pressure of the gas to be measured is measured based on a detection result of the ion current value, a cathode current is supplied to the cathode electrode such that an emission current flowing between the cathode electrode and the anode electrode becomes constant. When a partial pressure of the gas to be measured is not measured, a constant current having a current value less than that of the cathode current is supplied to the cathode electrode.

Abstract: A mass spectrometry unit of the present invention includes a mass spectrometry portion that detects ion current values of a gas to be measured according to mass-to-charge ratio, to thereby measure partial pressures of the gas to be measured. The mass spectrometry unit further includes: a control portion for preliminary storing a record of a mass-to-charge ratio of a specific gas that decreases a function of a specific portion of the mass spectrometry unit, in which if an ion current value with the mass-to-charge ratio of the specific gas detected by the mass spectrometry portion is not less than a predetermined value, the control portion outputs a warning signal denoting a functional decrease in the specific portion.

Abstract: A method of controlling a mass spectrometer comprises the steps of: supplying a current to a cathode electrode of an ion source having the cathode electrode and an anode electrode, and ionizing a molecules of a gas to be measured; selecting ions generated in the ion source by mass-to-charge ratio; and detecting an ion current value of the selected ions. When a partial pressure of the gas to be measured is measured based on a detection result of the ion current value, a cathode current is supplied to the cathode electrode such that an emission current flowing between the cathode electrode and the anode electrode becomes constant. When a partial pressure of the gas to be measured is not measured, a constant current having a current value less than that of the cathode current is supplied to the cathode electrode.

Abstract: A vertical wafer supporting boat is provided in which adequate reaction gas is supplied to the portion of a wafer surface to be treated which is inserted in holding grooves in members of the wafer supporting boat during the heat treatment and thus uniform heat treatment is achieved across the surface of each wafer. The particular groove shape preferably exploits the rotation of the boat in a vertical furnace to thereby uniformly supply the reaction gas on the entire surface to be treated of each of the wafers disposed in the boat. The holding grooves are inclined relative to a direction tangent to a wafer edge in order that the clearance facing the surface to be treated of a wafer is profiled to have an edge-like space by gradually increasing the width in the tangential direction of the wafer and, preferably, the internal groove surface opposed to the surface to be treated of the wafer is inclined to increase in width toward the center of the wafer.