Tung & Associates
Vertical cassette elevator and load lock viewer
 A viewfinder device for viewing the interior of dark, inaccessible areas and environments, such as the chamber of a vertical cassette elevator or load lock used in semiconductor wafer fabricating systems, consisting of three housing sections forming a displaced optical path from the interior of the chamber on which the device is mounted through a viewport on the chamber to a viewfinder and viewing lens at the observing end of the device. The first housing section is mounted on a suitable rotater assembly on the top wall of the chamber to the viewport by an adapter member, and is fitted in its side with an illuminating means, for illuminating the interior of the chamber. An image reflected from the chamber interior passes up through the optical column formed by the first section and is reflected by a reflector mirror, disposed at an angle at the top of the first section, through the optical column formed within the center section. A second reflector mirror is disposed at the other end of the center section arranged in a plane parallel to that of the first reflector mirror so as to displace the axis of the image by the distance between the mirrors. The displaced image is then reflected to a viewfinder, including a viewing lens, for observation by a technician in the event that a question or problem arises during the operating of the processing machinery requiring the viewing of the interior of the VCE or LL chambers. To facilitate this viewing, the viewfinder device can be rotated through a complete angle of 360.degree. by means of the rotater assembly. 
Taiwan Semiconductor Manufacturing Company, Ltd.
H G G
H01L G02B G02B
inventional inventional inventional
Jia-Rong
Chen