Patent ID: 7755065

Claim:
A focused ion beam apparatus for irradiating an ion beam having a beam size narrowed to or below a predetermined value on a sample, observing or analyzing a top surface of the sample or processing the top surface of the sample, comprising: a plasma generator having a plasma torch which lets plasma flow out while maintaining plasma inside, wherein the plasma generator generates an inductively coupled plasma, and includes: a work coil that is wound around the plasma torch to generate a high-frequency magnetic field; a high-frequency power supply that supplies high-frequency power to the work coil; and a plasma gas feeding unit that feeds a gas to become plasma to the plasma torch; a differential exhaust chamber that is coupled with the plasma torch to cause adiabatic expansion of the plasma flowing out of the plasma torch to form a supersonic flow of the plasma; a torch orifice disposed between the plasma torch and the differential exhaust chamber, wherein the torch orifice comprises a diameter set equal to or greater than twice a thickness of an ion sheath produced by the plasma generator; a drawing orifice provided at the differential exhaust chamber and faced to the plasma torch to draw ions from the supersonic flow of the plasma; a drawing electrode that electrostatically accelerates ions having passed through the drawing orifice; and an ion optical system that irradiates and focuses the ions drawn from the drawing electrode on the sample by optically manipulating the ions.