ACTINIC RADIATION SOURCE HAVING ANODE THAT INCLUDES A WINDOW AREA FORMED BY A THIN, MONOLITHIC SILICON MEMBRANE

摘要

An actinic radiation source (20) includes an anode (36) upon which an electron beam from a cathode ray gun (24) impinges. The anode (36) includes a window area (52) formed by a silicon membrane. The electron beam upon striking the anode (36) permeates the window area (52) to penetrate into medium surrounding actinic radiation source (20). A method for making an anode (36) uses a substrate having both a thin first layer (44) and a thicker second layer (46) of single crystal silicon material between which is interposed a layer of etch stop material (48). The second layer (46) is anisotropically etched to the etch stop material (48) to define the electron beam window area (52) on the first layer (44). That portion of the etch stop layer (48) exposed by etching through the second layer (46) is then removed. The anode (36) thus fabricated has a thin, monolithic, low-stress and defect-free silicon membrane electron beam window area (52) provided by the first layer of the substrate.