Systems and methods for a gas field ion microscope

Abstract

In one aspect the invention provides a gas field ion microscope that includes an ion source in connection with an optical column, such that an ion beam generated at the ion source travels through the optical column and impinges on a sample. The ion source includes an emitter having a width that tapers to a tip comprising a few atoms. In other aspects, the invention provides methods for using the ion microscope to analyze samples and enhancing the performance of a gas field ion source.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures depict certain illustrative embodiments of the invention in which like reference numerals refer to like elements. These depicted embodiments may not be drawn to scale and are to be understood as illustrative of the invention and not as limiting in any way.

FIG. 1 is a block diagram depicting an ion microscope according to one illustrative embodiment of the invention.

FIG. 2 is a zoomed-in view of a tip of an ion source in an ion microscope according to one illustrative embodiment of the invention.

FIG. 3 is a zoomed-in view of a tip of an ion source showing the formation of a virtual source according to one illustrative embodiment of the invention.

FIG. 4 is a chart showing the relationship between the ion beam current and gas pressure for an ion microscope according to one illustrative embodiment of the invention.

FIG. 5 is a block diagram depicting a transmission ion microscope according to one illustrative embodiment of the invention.

FIG. 6 depicts a conversion plate configured with an ion microscope according to one illustrative embodiment of the invention.

FIG. 7 is a block diagram depicting the acceleration and deceleration of an ion beam in an ion microscope according to one illustrative embodiment of the invention.

Claims

1. An ion microscope, comprising an ion source, capable of generating an ion beam, having a distal end, that tapers to an atomic shelf including a substantially constant predetermined number of atoms,a sample holder, for securing a sample and physically separated from the distal end of the ion source,a detector, for detecting particles emitted from the sample in response to the ion beam, andan optical column extending from the ion source towards the sample.

2. The ion microscope of claim 1, further comprising a gas source capable of delivering a gas to a region near the distal end of the ion source.

3. The ion microscope of claim 2, wherein the gas source delivers gas at a predetermined pressure and comprises an input module capable of receiving instructions to change the predetermined pressure.

4. The ion microscope of claim 1, comprising a conversion plate disposed near the sample holder such that the particles emitted from the sample strike a portion of the conversion plate and wherein the conversion plate is capable of emitting a second set of particles in response to the particles emitted from the sample.

5. The ion microscope of claim 1, wherein the distance from an end of the optical column to the sample is greater than 50 mm.

6. The ion microscope of claim 1, wherein the optical column includes electrodes placed at one or more locations between the distal end of the emitter and the sample such that the particle beam is accelerated and/or decelerated.

7. A method of analyzing a sample using an ion microscope, comprising the steps of providing an ion microscope, comprising an ion source, capable of generating an ion beam, having a distal end that tapers to an atomic shelf including a substantially constant predetermined number of atoms,a sample holder, for securing a sample and physically separated from the distal end of the ion source,a detector, for detecting particles emitted from the sample in response to the ion beam, andan optical column extending from the ion source towards the sample,securing the sample to the sample holder,operating the ion microscope, such that the ion beam strikes a portion of a surface of the sample,detecting particles emitted from the sample in response to the ion beam,

8. The method of claim 7, wherein the ion microscope comprises a gas source capable of delivering a gas to a region near the distal end of the ion source.

9. The method of claim 8, wherein an intensity of the ion beam is adjusted based at least in part on a concentration of gas in the region near the distal end of the ion source.

10. The method of claim 7, wherein the ion microscope comprises a conversion plate disposed near the sample holder and the step of detecting includes detecting a second set of particles emitted from the conversion plate such that a characteristic of particles emitted from the sample in response to the ion beam is modified.

11. The method of claim 7, wherein detecting particles emitted from the sample includes detecting a characteristic of particles emitted from the sample.

12. The method of claim 11, wherein the characteristic includes at least one of number of particles, particle energy, particle angles, particle polarization and de-excitation time.

13. The method of claim 12, wherein the particles emitted from the sample includes at least one of photons, electrons, ionized particles and neutral particles.

14. The method of claim 7, wherein the particle beam is accelerated and/or decelerated.