Emitter structure, gas ion source and focused ion beam system

Patent metadata

Field	Value
Publication number	US-9640361-B2
Application number	US-201514830106-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Mar 26, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A focused ion beam system includes a gas ion source and an emitter structure. The emitter structure includes a pair of conductive pins fixed to a base member, a filament connected between the pair of conductive pins, and an emitter which has a tip end with one atom or three atoms and which is connected to the filament. A supporting member is fixed to the base material, and the emitter is connected to the supporting member.

First claim

What is claimed is:

1. In a gas field ion source, an emitter structure comprising:
a base member to which are fixed two conductive pins;
a filament having two end portions connected to respective ones of the two conductive pins;
a supporting member connected to the base member; and
an emitter having a tip end with one atom or three atoms, the emitter being supported by the supporting member and connected to the filament.

2. The gas field ion source according to claim 1 ; wherein the tip end comprises tungsten (W) or iridium (Ir).

3. The gas field ion source according to claim 2 ; wherein the tip end comprises iridium (Ir) with one atom.

4. The gas field ion source according to claim 2 ; wherein the tip end comprises tungsten (W) with three atoms.

5. The gas field ion source according to claim 1 ; further including a surrounding member that extends downward from a peripheral edge of the base member and defining therewith an ion generating chamber, the lower portion of the base member and the emitter being situated within the ion generating chamber.

6. The gas field ion source according to claim 5 ; further comprising
a gas source configured to supply a gas into the ion generating chamber;
a cooling unit configured to cool the emitter,
an extraction electrode disposed at a lower end portion of the ion generating chamber spaced from the tip of the emitter; and
an extraction electrode power source unit which is configured to apply an extraction voltage between the emitter and the extraction electrode to ionize the gas into gas ions at the tip of the emitter and extract the gas ions toward the extraction electrode,
wherein the gas is any one selected from He, Ne, Kr, Xe, H2 and O2.

7. The gas field ion source according to claim 6 ; wherein the gas is a mixture of two or more gases.

8. A focused ion beam system, comprising:
the gas field ion source according to claim 6 ; and
a beam optical system configured to convert the extracted gas ions into a focused ion beam and irradiate a sample with the focused ion beam,
wherein the type of gas supplied into the ion generating chamber is selected according to the usage of the focused ion beam system.

Assignees

• Hitachi High-Tech Science Corp

Inventors

• Yasaka Anto
• Sugiyama Yasuhiko
• Oba Hiroshi

Classifications

• H01J2237/06316

  Schottky emission · CPC title

• H01J27/024

  Extraction optics, e.g. grids · CPC title

• H01J27/26 Primary

  using surface ionisation, e.g. field effect ion sources, thermionic ion sources (H01J27/20, H01J27/24 take precedence) · CPC title

• H01J37/08

  Ion sources; Ion guns · CPC title

• H01J3/04

  Ion guns · CPC title