公开(公告)号：JPH02276143A

公开(公告)日：1990-11-13

申请号：JP33880589

申请日：1989-12-28

Applicant: KOREA ELECTRONICS TELECOMM

Inventor： CHIE YOON KIYU ,  YANGU JIYON UTSUGU ,  II JIN HII ,  II JIEE SHIN ,  SHIMU KIYU FUAN ,  KANGU JIN YONGU

IPC: H01J35/22 ,  G03F7/20 ,  H01L21/00 ,  H05G2/00

Abstract: PURPOSE: To increase the stability of a light spot and remove contaminant periodically so that a continuous operation is made practicable, by adjusting the gas conductivity with the size of a hole provided in a metal disc located between a gas supply chamber and a discharge chamber. CONSTITUTION: The gas conductivity is adjusted with the size of a hole 23 provided in a metal disc 22 located between a gas supply chamber 30 and a discharge chamber 19, and thereby a differential vacuum is generated between the two chambers 30 and 19 so as to form a uniform flow, wherein the size of the hole 23 is made greater as going toward the center. Accordingly the gas flow can fill evenly the part behind the current curved surfaces 15, 16, 17, 18, which allows decreasing a change in the gas flow. The vessel from the terminating point of the center electrode 1 to the exhaust port 55a of an observing cylinder 56 is made in a shape circular, semi-circular, or elliptical, which prevents distortion of the gas flow and also potential distribution, and it is possible to establish good reproducibility of the position of the generation point 20.