Title:
OBJECT TESTER
Document Type and Number:
Japanese Patent JPH0249342
Kind Code:
A
Abstract:
PURPOSE: To focus electronic beam on a minimum diameter, stabilize a beam location and enable beam displacement by providing a magnetic diaphragm to separate a lens field for extraction of electron and void space imparting distributed electromagnetic field. CONSTITUTION: A coil 32 for generation of magnetic field is arranged near magnetic pole pieces 34 and 36 of an objective lens 8 and the coil 32 is constituted so that the magnetic field may have the same direction as that of the magnetic field generated between the magnetic pole pieces of the objective lens 8, two magnetic fields may be smoothly continuous and intensity of the magnetic field by the coil may be changed. The magnetic permeability of material of the magnetic pole pieces 34 and 36 of the objective lens 8 is changed according to locations and generation of the composite magnetic field of an objective lens field having a desired characteristic and detected magnetic field is made possible. Further, electron is displaced by crossing an object even if composite static magnetic field is generated within an electroless void space formed by a magnetic shield 22 and electron to be detected is deflected so as to be apart from an optical axis by composite static magnetic field. Namely, additional focusing is unnecessitated.
Inventors:
PIITAA KURUITO
ARUNO YAN BUREEKERU
JIYON ANSONI BUIINABURIISU
ARUNO YAN BUREEKERU
JIYON ANSONI BUIINABURIISU
Application Number:
JP11274089A
Publication Date:
February 19, 1990
Filing Date:
May 01, 1989
Export Citation:
Assignee:
PHILIPS NV
International Classes:
G01N23/225; G01Q30/06; H01J37/09; H01J37/141; H01J37/22; H01J37/244; H01J37/252; H01J37/256; (IPC1-7): G01N23/225; H01J37/22; H01J37/244; H01J37/252
Attorney, Agent or Firm:
Akihide Sugimura (1 outside)
Next Patent: JPH0249343