Focused ion beam system and a method of sample preparation and observation

• US 7,612,337 B2
• Filed: 01/18/2007
• Issued: 11/03/2009
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Suzuki, Yuya, Kamino, Takeo, Konno, Mitsuru, Ohnishi, Tsuyoshi, Yaguchi, Toshie
• Primary Examiner(s): Berman; Jack I
• Assistant Examiner(s): IPPOLITO, NICOLE MARIE
• Application Number:
  US11/654,685
• Publication Number:
  US 20070187597A1
• Time in Patent Office: 1,020 Days
• Field of Search: 250/309, 250/310, 250/306, 250/307, 250/491.1, 250/492.2, 250/492.21, 250/492.22, 250/492.1, 250/492.3, 250/311, 850/5, 850/7, 850/8, 850/9, 850/10, 430/296, 430/297, 430/298
• US Class Current: 250/310
• CPC Class Codes: H01J 2237/2516 Secondary particles mass or energy spectrometry
• CPC Class Codes: H01J 2237/31745 for preparing specimen to be viewed in microscopes or analyzed in microanalysers
• CPC Class Codes: H01J 37/3005 Observing the objects or the point of impact on the object
• CPC Class Codes: H01J 37/3056 for microworking, e. g. etching of gratings or trimming of electrical components

Abstract

A focused ion beam system capable of acquiring surface structure information, internal structure information, and internal composition information about a sample simultaneously from the same field of view of the sample. A method of sample preparation and observation employs such focused ion beam system to accurately set a sample processing position based on information about the structure and composition of the sample acquired from multiple directions of the sample, and to process and observe the sample. The system includes, in order to acquire the sample structure and composition information simultaneously, a secondary electron detector, a transmission electron detector, and an energy dispersive X-ray spectroscope or an electron energy loss spectroscope, and employs a stub having the sample rotating and tilting function. The method includes a marking process.

Claims

1. A focused ion beam system comprising:

an ion beam source which generates an ion beam;

a detector for obtaining surface structure information and either internal structure information or internal composition information about a sample based on the result of scanning the sample with an electron beam, wherein each information is obtained from the same field of view as a processing region which is set on the sample based on a secondary electron image obtained by scanning ion excitation of the sample; and

a processor for generating an image in which the surface structure information and internal structure information or internal composition information that is acquired of the sample are superposed,

wherein then a processing position of the sample is set based on the superposed image and the sample is processed using a focused ion beam, and

wherein the detector detects a secondary electron image based on scanning electron or scanning ion excitation and wherein the internal structure information or internal composition information about the sample is obtained using at least one of an energy dispersive X-ray spectroscope (EDX), an electron energy loss spectroscope (EELS) and a transmission electron detector, as the detector.

2. The focused ion beam system according to claim 1, wherein the surface structure information about the sample is obtained based on a secondary electron image that is obtained by scanning electron excitation of the sample, and wherein the internal structure information or internal composition information about the sample is obtained based on at least one of an elemental map image obtained from a characteristic X-ray, an image of scattered electrons, an image of transmission electrons, and an elemental map image obtained from transmission electrons, upon scanning electron excitation of the sample.

3. The focused ion beam system according to claim 1, comprising a stub for fixing a sample, wherein the stub is capable of causing one surface of the sample to be directed opposite an ion source or an electron source, and rotating a fixing plane thereof.

4. A focused ion beam system comprising:

a processor for processing a processing region on a sample using a focused ion beam wherein the processing region is set based on a secondary electron image obtained by scanning ion excitation of the sample;

a detector for obtaining surface structure information and either internal structure information or internal composition information about the sample, based on the result of scanning the sample with an electron beam; and

an actuator for actuating a stub, on which the sample is fixed, so as to apply it to the first or the second device,

wherein a processing region is set on the sample based on an image and then processed by the first device, the image having the surface structure information and the internal structure information or internal composition information about the sample obtained in the second device superposed therein.

5. The focused ion beam system according to claim 4, wherein in the detector, the surface structure information about the sample is obtained based on a secondary electron image obtained by scanning electron excitation of the sample, and the internal structure information or internal composition information about the sample is obtained based on at least one of an elemental map image obtained from a characteristic X-ray, an image of scattered electrons, an image of transmission electrons, and an elemental map image obtained from transmission electrons, upon scanning electron excitation of the sample.

6. The focused ion beam system according to claim 4, wherein the detector obtains a secondary electron image based on scanning electron or scanning ion excitation and wherein the internal structure information or internal composition information about the sample is obtained using at least one of an energy dispersive X-ray spectroscope, an electron energy loss spectroscope and a transmission electron detector, as the detector.

7. The focused ion beam system according to claim 5, wherein the detector obtains a secondary electron image based on scanning electron or scanning ion excitation and wherein the internal structure information or internal composition information about the sample is obtained using at least one of an energy dispersive X-ray spectroscope, an electron energy loss spectroscope and a transmission electron detector, as the detector.

8. A method of sample preparation and observation using a focused ion beam, comprising the steps of:

setting a processing region on a sample based on a secondary electron image based on scanning ion excitation of the sample;

obtaining surface structure information and either internal structure information or internal composition information about the sample based on the result of scanning the sample with an electron beam;

generating an image in which the surface structure information and either the internal structure information or internal composition information about the sample are superposed; and

setting a processing position on the sample based on the superposed image and processing the sample using a focused ion beam.

9. The method according to claim 8, wherein the surface structure information about the sample is obtained based on a secondary electron image based on scanning electron excitation of the sample, and wherein the internal structure information or internal composition information about the sample is obtained based on at least one of an elemental map image obtained from a characteristic X-ray, an image of scattered electrons, an image of transmission electrons, and an elemental map image obtained from transmission electrons, upon scanning electron excitation of the sample.

10. The method according to claim 8, wherein the sample is processed using a focused ion beam to provide it with a marking that can be recognized in terms of any of the surface structure information, internal structure information, and internal composition information about the sample, and wherein an image is generated with respect to the marking in which the surface structure information and the internal structure information or internal composition information about the sample are superposed.