Processing apparatus and method using a scanning electron microscope

• US 9,177,759 B2
• Filed: 06/11/2014
• Issued: 11/03/2015
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Li, Wen, Kadoi, Ryo, Kawano, Hajime, Takahashi, Hiroyuki
• Primary Examiner(s): IPPOLITO, NICOLE MARIE
• Application Number:
  US14/301,403
• Publication Number:
  US 20150041643A1
• Time in Patent Office: 510 Days
• Field of Search: 250/305, 250/306, 250/307, 250/309, 250/310, 250/311
• US Class Current: 1/1
• CPC Class Codes: H01J 2237/1504 Associated circuits
• CPC Class Codes: H01J 2237/151 Electrostatic means
• CPC Class Codes: H01J 2237/1536 Image distortions due to scanning
• CPC Class Codes: H01J 37/1471 for centering, aligning or positioning of ray or beam
• CPC Class Codes: H01J 37/265 Controlling the tube; circuit arrangements adapted to a particular application not otherwise provided, e.g. bright-field-dark-field illumination
• CPC Class Codes: H01J 37/28 with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

The present invention provides a processing apparatus using a scanning electron microscope, which includes the scanning electron microscope having an electron optical system radiating and scanning a focused electron beam on a sample placed on a stage to image the sample, and an image processing/control section which controls the scanning electron microscope and processes the image obtained by imaging with the scanning electron microscope. The electron optical system of the scanning electron microscope has image shift electrodes comprised of electrostatic electrodes, the image shift electrodes moving a position at which to apply the focused electron beam onto the sample with the stage stopped to thereby shift a region in which the sample is to be imaged.

Claims

1. A processing apparatus using a scanning electron microscope, comprising:

the scanning electron microscope having an electron optical system for imaging a sample, the electron optical system radiating and scanning a focused electron beam on the sample placed on a stage; and

an image processing/control section which controls the scanning electron microscope and processes an image obtained by imaging with the scanning electron microscope,

wherein the electron optical system of the scanning electron microscope has image shift electrodes comprised of electrostatic electrodes, the image shift electrodes moving a position at which to apply the focused electron beam onto the sample with the stage stopped to thereby shift a region in which the sample is to be imaged,

wherein each of the image shift electrodes comprised of the electrostatic electrodes has a function of a deflection electrode for scanning the electron beam, and

wherein the image processing/control section has an image shift deflection control unit which outputs a signal to the image shift electrodes, the output signal being obtained by superposing an image shift control signal and a deflection signal for deflecting the electron beam on each other.

2. The processing apparatus according to claim 1,

wherein the image processing/control section applies a signal to the image shift electrodes, the applied signal correcting an aberration of the electron beam generated by shifting the imaging region of the sample with the image shift electrodes, the applied signal also correcting a positional displacement of the stopped stage.

3. The processing apparatus according to claim 1, wherein

the electron optical system has deflection electrodes which scan the electron beam, and

the image processing/control section has an image shift control unit controlling the image shift electrodes and a deflection control unit controlling the deflection electrodes.

4. The processing apparatus according to claim 1,

wherein the image shift deflection control unit has a high-speed driver having a frequency of more than 1 MHz and a deflection signal input part, the high-speed driver being placed in floating from a common ground of the apparatus and generating the image shift control signal, the deflection signal input part inputting the deflection signal for deflecting the electron beam to the high-speed driver via an isolator which isolates the driver from the deflection signal generator based on the common ground of the apparatus.

5. The processing apparatus according to claim 1, wherein the image shift deflection control unit has circuits divided and arranged on a plurality of substrates different in substrate potential.

6. A processing method using a scanning electron microscope, comprising the steps of:

radiating and scanning a focused electron beam on a sample placed on a stage by an electron optical system of the scanning electron microscope to image the sample;

inputting a signal to the image shift electrodes comprised of the electrostatic electrodes, the input signal being obtained by superposing an image shift control signal and a deflection signal for deflecting the electron beam on each other;

controlling the focused electron beam with the image shift electrodes; and

thereby shifting the imaging region of the sample and scanning the shifted imaging region by the deflection signal; and

processing an image obtained by imaging with the scanning electron microscope,

wherein the radiating and scanning with the electron beam focused by the electron optical system of the scanning electron microscope includes moving a position at which to apply the focused electron beam onto the sample with the stage stopped by using image shift electrodes comprised of electrostatic electrodes to thereby shift a region in which the sample is to be imaged.

7. The processing method according to claim 6, further comprising the steps of:

correcting an aberration of the electron beam, the aberration of the electron beam being generated by shifting the imaging region of the sample with the image shift electrodes comprised of the electrostatic electrodes; and

correcting a positional displacement of the stopped stage.

8. The processing method according to claim 6, further comprising the steps of:

deflecting the focused electron beam with deflection electrodes with the imaging region of the sample shifted by the image shift electrodes;

scanning the imaging region of the sample; and

thereby imaging the shifted imaging region.

9. The processing method according to claim 6, further comprising the steps of:

generating the image shift control signal with a high-speed driver having a frequency of more than 1 MHz placed in floating from a common ground of the apparatus;

inputting the deflection signal to the high-speed driver through an isolator which isolates the driver from the deflection signal generated based on the common ground of the apparatus the deflection signal deflecting the electron beam;

inputting a signal to the image shift electrodes, the input signal being obtained by superposing the image shift control signal and the deflection signal on each other, and

thereby controlling the image shift electrodes comprised of electrostatic electrodes.

10. The processing method according to claim 6, further comprising the step of controlling the image shift electrodes using circuits divided and arranged on a plurality of substrates different in substrate potential.