ION Beam System and Machining Method

Abstract

An ion beam machining system which performs a predetermined machining of a sample by irradiating the sample with an ion beam includes a beam spot former which forms a beam spot shape of the ion beam to be non-axially symmetric in a perpendicular plane with respect to an irradiation axis of the ion beam, and an axis orientator which orients one axis of the beam spot at the ion beam irradiation position on the sample in a predetermined direction.

1 . An ion beam machining system which performs a predetermined machining of a sample by irradiating the sample with an ion beam, comprising:
 means for forming a beam spot shape of the ion beam to be non-axially symmetric in a perpendicular plane with respect to an irradiation axis of the ion beam; and   means for orienting one axis of the beam spot at the ion beam irradiation position on the sample in a predetermined direction.   
     
     
         2 . The ion beam machining device according to  claim 1 , further comprising:
 a stage for mounting the sample to be machined; and   an ion beam column which irradiates or scans the sample by the ion beam; and   is an SEM column which irradiates the sample by an electron beam;   wherein the ion beam column includes a mass separator.   
     
     
         3 . The ion beam machining system according to  claim 1 , wherein the non-axially symmetric shape of the beam spot is an ellipse. 
     
     
         4 . An ion beam machining method which machines a cross-section of a sample by an ion beam system including an ion source, an irradiation optical system which irradiates the sample by an ion beam extracted from the ion source, a sample stage which holds the sample, and an ion beam controller which controls the ion beam to machine the cross-section of the sample, comprising the steps of:
 adjusting a shape of a beam spot of the ion beam to be non-axially symmetric with respect to an irradiation axis of the ion beam, the cross-section of the sample and a long axis of the beam spot of the ion beam being parallel when the sample held on the sample stage is machined; and   observing the machined cross-section of the sample by a charged particle beam from a direction in which a segment which is a projection of the observation direction on a sample mounting surface of the sample stage is perpendicular to the long axis of the beam spot of the ion beam.   
     
     
         5 . The ion beam machining system according to  claim 4 , further comprising the step of forming the ion beam utilizing a projection ion irradiation system. 
     
     
         6 . An ion beam machining system comprising:
 an ion source;   at least one lens which converges an ion beam emitted from the ion source;   a sample stage which holds a sample to be machined; and   an ion beam controller which controls the ion beam to machine a cross-section of the sample;   wherein the ion beam controller performs control so that the at least one lens which converges the ion beam is a lens which enables aberrations in two directions perpendicular to an ion beam irradiation axis to be different; and   wherein relative positions of the sample held in the sample stage and the ion beam are such that one of the two directions in which the aberration is smaller than an other of the two directions faces the machined cross-section of the sample.   
     
     
         7 . The ion beam machining system according to  claim 6 , further comprising an observation controller which performs control to enable observation of the machined cross-section of the sample by an electron beam or the ion beam, and control of lens magnification of the at least one lens in a direction perpendicular to the cross-section of the sample when a rectangular hole is formed in the sample by ion beam irradiation to be less than lens magnification of the at least one lens in the direction perpendicular to the ion beam irradiation axis and parallel to the machined cross-section of the sample. 
     
     
         8 . The ion beam machining system according to  claim 6 , wherein the ion beam emitted from the ion source comprises one of an inert gas, oxygen, and nitrogen as an element thereof.