VIEWING PORT AND AUXILIARY TRANSLUCENT BODY FOR VIEWING PORT

摘要

PURPOSE: To make it possible to suppress the peeling of the thin film in the part of a viewing port and to sufficiently clean the part of the viewing port as well by etching. ;CONSTITUTION: This viewing port is fitted into the hole 2 of the wall 1 of a vacuum discharge chamber and allows the transmission of light of a prescribed wavelength while hermetically closing the hole 2. The viewing port has the translucent body 3 which is so arranged that the surface 30 on the internal side of vacuum discharge chamber forms the same curved surface or the same plane as the inside surface 10 of the wall 1. The sharp angle part in no longer formed in the part of the viewing port and, therefore, the peeling of the thin films is suppress even if the thin film is deposited thereon.;COPYRIGHT: (C)1996,JPO