CHARGED PARTICLE BEAM APPARATUS, AND METHOD OF CONTROLLING THE SAME

• Main Authors: TODOKORO HIDEO, KOKUBO SHIGERU, KATAGIRI SOUICHI, KASUYA KEIGO, OSHIMA TAKU
• Format: Patent
• Language: English; Japanese
• Published: 25.12.2014
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a charged particle beam apparatus which can emit a stable electron beam, having high brightness and a narrow energy width.SOLUTION: A charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10Pa or less. The apparatus is so constituted as to use electron beams having an electron-beam-center radiation angle of 1×10str or less among the emitted electron beams, and to use the electric current thereof, the second order derivative of which with respect to the time of the electric current of the electron beam is negative or zero and which decreases at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam. The field emission electron source is repeatedly heated to keep the electric current of the electron beam to be emitted, at a predetermined value or higher. 【課題】高輝度でエネルギー幅が狭く、安定した電子線を得ることが出来る荷電粒子線装置を提供する。【解決手段】電界放射電子源、それに電界を印加する電極と、電界放射電子源のまわりの圧力を１?１０−８Ｐａ以下に維持する真空排気部とを備え、放射させた電子線のうち、電子線中央の放射角１?１０−２ｓｔｒ以内の電子線を用い、電子線の電流の時間に関する二階微分が負または０で、かつ電流の減少度合いが１時間当たり１０％以内となる電流を用いる構成を有する。さらに、電界放射電子源の加熱部と、電子線の電流の検出部とを備え、電界放射電子源を繰り返し加熱することで、放射される電子線の電流を所定の値以上に維持する。【選択図】図３