公开(公告)号：WO1990005990A1

公开(公告)日：1990-05-31

申请号：PCT/US1989005252

申请日：1989-11-14

Applicant: ELECTRON VISION CORPORATION

Inventor： ELECTRON VISION CORPORATION ,  LIVESAY, William, R.

IPC: H01J37/077

CPC classification number: H01J37/077 ,  H01J3/025

Abstract: A large-area electron source (22) which can operate continuously, stably, and indefinitely in a poor vacuum (20) environment. The source includes a glow discharge cathode, appropriately positioned with respect to a target anode (30) and a fine-mesh grid (26) spaced from the cathode (22) by a distance less than the mean free path length of electrons leaving the cathode (22), the grid (26) being electrically biased to control the electron beam current over a wide range with only small grid voltage changes. An accelerating voltage (29) applied to the cathode (22) can be varied continuously from as low as a few hundred volts to 30 KeV or greater and the source will continue to operate satisfactorily. Further, the grid (26) is made of a fine mesh wire of sufficiently small dimensions as to not be resolvable in the target plane (30). A further refinement of the device utilizes scanning coils (34) to achieve additional uniformity of the incident beam at the target plane (30). The basic apparatus of the invention can be combined with other features, for use in shadow mask lithography, resist sensitivity measurement, lift off processing, and resist curing.