CLEANING METHOD FOR CHARGED BEAM DRAWING LENS-BARREL, CHARGED BEAM DRAWING LENS BARREL

摘要

PROBLEM TO BE SOLVED: To clean inside of a charged beam drawing lens-barrel without disassembling it. ;SOLUTION: Ozon O₃ is supplied from an O₃ generating unit 22 to a charged beam drawing lens-barrel 10 through a constant delivery valve 23, and at the same time, the degree of vacuum inside the charged beam drawing lens-barrel 10 is maintained at 10^-3-10^-5 Pa by ion pumps 18A, 18B, 18C, and the charged beam B is passed through the lens-barrel 10. The charged beam B collides with a surface of a member inside of the lens-barrel 10 and generates scattered electrons. These scattered electrons assists the compounding of the bumping material of the resist flowing into the charged beam drawing lens-barrel 10 and O₃ at the time of drawing and O₃, and decomposes the bumping material. The decomposed bumping material of the resist is discharged to the outside by means of evacuation of the ion pumps 18A, 18B, 18C.;COPYRIGHT: (C)1999,JPO