The Perkin-elmer Corporation

The United States of America As Represented by the Administrator of the

John W Vorreiter

William A Eckes

John C Wiesner

Robert L Dean

Charles E Shepard

Russell H Rhoades

Disclosed are passive electrostatic particle collectors (10 & 12) for use in vacuum chambers (24 & 32) especially for a particle beam machine system (30 & 36) to collect particulates, such as dust and debris, generated by moving parts (16) within such chambers (24 & 32). These electrostatic particle collectors (10 & 12) comprise Tourmaline crystals (12) mounted on a bracket plate (10) and strategically located where dust and debris are generated. Also disclosed is a method of removing particulate material in vacuum chambers generated by moving parts by passive electrostatic particle collectors.

Passive electrostatic vacuum particle collector

An electrostatic cassette assembly comprising, a cassette body having a central opening for receiving a wafer to be processed in a particle beam lithographic system, a charge plate with a top surface having a coating of dielectric (nonconductive) material or a plurality of nonconductive means, or both, on which the wafer is supported, means for forcing said charge plate and wafer into contact with stop means to hold the wafer rigidly in said cassette assembly, and means for applying a potential difference between the wafer and the charge plate to flatten said wafer by Coulombic force so that the wafer is held both mechanically and electrostatically in said cassette assembly. Means are also provided for insuring a good electrical contact with the wafer and for aligning the wafer in the cassette assembly.

Electrostatic cassette

The present invention is directed to a support structure formed from a compound strap consisting of two or more links of different thicknesses. More particularly, the compound strap includes a thinner link which is connected to the cool end of the inner storage tank's outer wall and a thicker link which is connected to the warmer outer wall of a relatively larger outer tank which encloses the inner tank to provide a vacuum space. This vacuum space around the inner tank contains the thermal support straps preferably made of fiberglass epoxy resin material used to support the inner tank from the inner wall of the outer tank. The compound strap of the present invention minimizes the heat leak between the inner tank and the outer tank.

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Sunnyvale, CA, United States of America

John W Vorreiter