ELECTRON BEAM DEVICE

摘要

PURPOSE:To easily establish the uniformity of beam intensity by obtaining the control value of a bias resistance or a bias voltage in accordance with a beam current under the condition that the intensity distribution and the luminance of an electron beam or beam dimensions are fixed. CONSTITUTION:An electron gun 1 is composed of an LaB monocrystal chip 1a and a Wenhnelt 1b which are arranged by opposing to a positive electrode 2. The electron gun 1 is energized by a high-voltage power source 3 and heated by a heater power source 4 to establish the bias by a resistance circuit 5. A current detector 6 detects an operating current IR. A gold narrow wire 24 and a Faraday cup 26 measuring the intensity distribution and the dimensions of an electron beam are provided at the position of a sample surface and an electron beam current is detected. A bias resistance is adjusted by detecting the beam current after applying deflecting scan to the electron beam and by calculating the optimum bias from a change in current.