Inspection system and inspection image data generation method

Patent metadata

Field	Value
Publication number	US-10074510-B2
Application number	US-201414455276-A
Country	US
Kind code	B2
Filing date	Aug 8, 2014
Priority date	Aug 9, 2013
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

An inspection system includes a TDI sensor that integrates amounts of secondary charged particles or electromagnetic waves along a predetermined direction at every timing at which a transfer clock is inputted and sequentially transfers the amounts of secondary charged particles or electromagnetic waves so integrated, and a deflector which deflects, based on a difference between an actual position and a target position of the inspection target, the secondary charged particles or electromagnetic waves directed towards the TDI sensor in a direction in which the difference is offset. The target position is set into something like a step-and-riser shape in which the target position is kept staying in the same position by a predetermined period of time that is equal to or shorter than a period of time from an input of the transfer clock to an input of the following transfer clock and thereafter rises by a predetermined distance.

First claim

What is claimed is:

1. An inspection system comprising:
a primary optical system that has an electron source that irradiates charged particles in the form of a beam;
a current detection unit that detects an emission current value of the beam irradiated from the electron source;
an imaging unit that has an imaging element that detects an amount of secondary charged particles that are obtained by irradiating the beam on to an inspection target;
an image data generation unit that generates image data based on the results of the imaging by the imaging unit;
a correction unit that corrects the results of the imaging or the image data based on the emission current value so detected; and
a movable unit that can hold an inspection target to move the inspection target through a position where the beam is irradiated by the primary optical system, in a predetermined direction, wherein
the imaging unit comprises a TDI sensor having imaging elements that are aligned in the predetermined number of stages in a predetermined direction and configured to integrate amounts of secondary charged particles that are obtained by irradiating the beam on to the inspection target while moving the movable unit in the predetermined direction, through a time delay integration system along a predetermined direction, and
the correction unit corrects, based on a mean value of emission current values that are detected by the current detection unit during a period of integration during which amounts of secondary charged particles are integrated by the number of stages by the TDI sensor, the results of the imaging or the image data corresponding to the amounts of secondary charged particles that are integrated during the period of integration.

2. The inspection system according to claim 1 , wherein
the correction unit executes a correction so as to increase a luminance value that the results of the imaging or the image data exhibits in the event that the detected emission current value is smaller than the target value.

3. The inspection system according to claim 1 , wherein
the correction unit executes a correction so as to decrease a luminance value that the results of the imaging or the image data exhibits in the event that the detected emission current value is larger than the target value.

4. The inspection system according to claim 1 , comprising further:
a feedback control unit that executes a feedback control based on the detected emission current value so that the variation in emission current value is suppressed.

5. The inspection system according to claim 1 , wherein the correction unit executes the correction based on a predetermined target emission current value and the detected emission current value.

Assignees

• Ebara Corp

Inventors

• Suematsu Kenichi
• Yoshikawa Shoji

Classifications

• H01J37/20 Primary

  Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support · CPC title

• H01J37/285

  Emission microscopes, e.g. field-emission microscopes · CPC title

• H01J2237/20228

  Mechanical X-Y scanning · CPC title