Abstract: A method for preparing a positive photoresist layer is provided. In this method, a photoresist composition is drop-wise applied on an insulator layer or a conductive metal layer formed on a substrate. The photoresist composition includes a polymer resin, a sensitizer for changing solubility of the photoresist layer when exposed and a solvent. The coated substrate is rotated at the speed of 1,250 to 1,350 rpm for 4.2 to 4.8 seconds. The coated substrate is then dried and the dried substrate is exposed to some form of radiation. Next, the exposed portion is removed by using an alkaline developing solution. The solvent preferably includes 3-methoxybutyl acetate and 4-butyrolactone, or includes 3-methoxybutyl acetate, 2-heptanone, and 4-butyrolactone.

Abstract: A pretreatment system for analyzing impurities contained in a flat sample contains a cylindrical lower case having a stepped portion on which the flat sample is seated. The stepped portion is formed in an circumferential inner surface of the cylindrical lower case. A cylindrical upper case is detachably attached to an upper surface of the lower case, and has a supply passage through which a predetermined amount of pretreatment solution can be supplied to the flat sample. A cover closes off the upper surface of the upper case.

Abstract: An ion chromatography system analyzes the environment in semiconductor equipment for foreign materials. The system includes an impinger section for preparing a sample of the atmosphere, and an ion chromatography section. The impinger section includes an absorbent solution vessel, suction and exhaust piping connecting the vessel to the environment, and a pump for transporting atmosphere under pressure. The ion chromatography section includes a guard column, a separation column, and a detector. The suction pipe has an intake port positioned at a target site whose environment is to be analyzed. The impinger section is connected to the ion chromatography section so that the absorbent solution of the vessel directly enters the ion chromatography section. To promote the absorption of the atmosphere into the solution, the absorbent solution vessel may be in the form of an elongate diffusion scrubber having an outer cylindrical vessel and an inner tube made of a selective membrane.

Abstract: A sample solution contained in a sample vessel is analyzed using a positive ion detector and a negative ion detector. The positive ion detector and the negative ion detector are supplied with the sample solution from the sample vessel, while isolating the positive ion detector and the negative ion detector from one another. Accordingly, the sample solution is not supplied from the positive ion detector to the negative ion detector, and the sample solution is not supplied from the negative ion detector to the positive ion detector. The positive ion detector and negative ion detector are preferably supplied with sample solution from the sample vessel using a bidirectional valve having an input port and first and second output ports. The input port is connected to the sample vessel, the first output port is connected to the first detector, and the second output port is connected to the second detector.