Inspection system by charged particle beam and method of manufacturing devices using the system

• US 7,135,676 B2
• Filed: 06/27/2001
• Issued: 11/14/2006
• Est. Priority Date: 06/27/2000
• Status: Expired due to Fees

• Current Assignee: Ebara Corporation, Nikon Corporation
• Original Assignee: Ebara Corporation
• Inventors: Kimba, Toshifumi, Yoshikawa, Shoji, Noji, Nobuharu, Sobukawa, Hirosi, Satake, Tohru, Saito, Mutsumi, Nakasuji, Mamoru, Karimata, Tsutomu, Oowada, Shin, Hamashima, Muneki, Takagi, Toru
• Primary Examiner(s): Berman, Jack I.
• Application Number:
  US09/891,611
• Publication Number:
  US 20020033449A1
• Time in Patent Office: 1,966 Days
• Field of Search: 250/310, 250/396.R, 250/398
• US Class Current: 250/310
• CPC Class Codes: G01N 23/225 using electron or ion
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: H01J 2237/0435 Multi-aperture
• CPC Class Codes: H01J 2237/057 Energy or mass filtering
• CPC Class Codes: H01J 2237/06316 Schottky emission
• CPC Class Codes: H01J 2237/082 Electron beam
• CPC Class Codes: H01J 2237/202 Movement
• CPC Class Codes: H01J 2237/20228 Mechanical X-Y scanning
• CPC Class Codes: H01J 2237/204 Means for introducing and/or outputting objects locks H01J2237/184
• CPC Class Codes: H01J 2237/22 Treatment of data mixing signals H01J2237/24495
• CPC Class Codes: H01J 2237/2446 Position sensitive detectors
• CPC Class Codes: H01J 2237/24485 Energy spectrometers
• CPC Class Codes: H01J 2237/24564 Measurements of electric or magnetic variables, e.g. voltage, current, frequency
• CPC Class Codes: H01J 2237/248 Components associated with the control of the tube
• CPC Class Codes: H01J 2237/2482 Optical means
• CPC Class Codes: H01J 2237/2806 Secondary charged particle
• CPC Class Codes: H01J 2237/2816 Length
• CPC Class Codes: H01J 2237/2817 Pattern inspection
• CPC Class Codes: H01J 37/05 Electron or ion-optical arrangements for separating electrons or ions according to their energy or massparticle separator tubes H01J49/00
• CPC Class Codes: H01J 37/06 Electron sources; Electron guns electron sources in general H01J1/02, H01J19/02; electron guns in general H01J3/02
• CPC Class Codes: H01J 37/073 : Electron guns using field emission, photo emission, or secondary emission electron sources
• CPC Class Codes: H01J 37/075 : Electron guns using thermionic emission from cathodes heated by particle bombardment or by irradiation, e.g. by laser
• CPC Class Codes: H01J 37/185 : Means for transferring objects between different enclosures of different pressure or atmosphere
• CPC Class Codes: H01J 37/20 : Means for supporting or positioning the objects or the material; Means for adjusting diaphragms or lenses associated with the support introducing the objects H01J37/18
• CPC Class Codes: H01J 37/222 : Image processing arrangements associated with the tube image data processing or generation, in general G06T
• CPC Class Codes: H01J 37/226 : Optical arrangements for illuminating the object; optical arrangements for collecting light from the object
• CPC Class Codes: H01J 37/244 : Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/28 : with scanning beams H01J37/268, H01J37/292, H01J37/2955 take precedence

Abstract

An inspection apparatus and a semiconductor device manufacturing method using the same. The inspection apparatus is used for defect inspection, line width measurement, surface potential measurement or the like of a sample such as a wafer. In the inspection apparatus, a plurality of charged particles is delivered from a primary optical system to the sample, and secondary charged particles emitted from the sample are separated from the primary optical system and introduced through a secondary optical system to a detector. Irradiation of the charged particles is conducted while moving the sample. Irradiation spots of the charged particles are arranged by N rows along a moving direction of the sample and by M columns along a direction perpendicular thereto. Every row of the irradiation spots of the charged particles is shifted successively by a predetermined amount in a direction perpendicular to the moving direction of the sample.

Claims

1. An inspection apparatus (4000) comprising:

a primary electronic optical system with an optical axis for irradiating a surface of a sample by a plurality of primary charged particles; and

a secondary electronic optical system for leading secondary charged particles emitted from each point of irradiation by the plurality of the primary charged particles formed on the surface of the sample to a secondary electron detector after separation from the primary electronic optical system by accelerating the secondary charged particles by an electric field applied between an objective lens and the surface of the sample, converging the secondary charged particles accelerated, and separating the secondary charged particles from the first optical system by a separator, wherein said separator is disposed between the objective lens and a neighbor lens of said objective lens at the side of a beam source.

2. A method for manufacturing devices comprising the steps of:

a. providing a wafer;

b. processing the wafer;

c. detecting a defect on the wafer using the inspection apparatus of claim 1;

d. repeating necessary times of the steps b and c;

e. assembling the wafer into a device.

3. An inspection apparatus for inspecting a sample using a plurality of beams, comprising:

a plurality of primary charged particle beam irradiation systems each having a beam source, a lens and a deflector and adapted to form a plurality of points of irradiation with primary charged particle beams on the surface of the sample using an aperture plate,

a plurality of secondary charged particle optical systems each corresponding to each primary charged particle beam irradiation system, each of the secondary charged particle optical systems having a lens and a plurality of secondary charged particle detectors and

an objective lens and a separator which are common to each of the primary charged particle beam irradiation systems and corresponding secondary charged particle optical system,

wherein secondary charged particles are separated from the primary charged particle beams after they pass through the objective lens before they enter to the next lens.

4. An inspection apparatus (4100) comprising:

a plurality of optical systems each having a beam source for irradiating output beam and focusing and irradiating beam passed through the optical system on a sample surface, wherein secondary charged particle generated from the sample is separated from the optical system and the separated secondary charged particle is delivered into a detector so as to be detected, wherein said plurality of optical systems are disposed in two row and multiple columns, and the detectors in the first row and the detectors in the second row are disposed oppositely each other in order not to interfere with each other.

5. An inspection apparatus for inspecting a sample using a plurality of beams, comprising:

a plurality of primary charged particle beam irradiation systems each having a beam source, a lens and a deflector and adapted to form a plurality of points of irradiation with primary charged particle beams on the surface of the sample using an aperture plate,

a plurality of secondary charged particle optical systems each corresponding to each primary charged particle beam irradiation system, each of the secondary charged particle optical systems having a lens and a plurality of secondary charged particle detectors and

an objective lens and a separator which are common to each of the primary charged particle beam irradiation systems and corresponding secondary charged particle optical system,

wherein secondary charged particles are separated from the primary charged particle beams after they pass through the objective lens before they enter to the next lens,

wherein the primary charged particle beam irradiation system and the corresponding secondary charged particle optical systems are disposed in two rows and in plural columns so as to prevent a path of secondary charged particles deflected by one of the separators from interfering with other column of a path of the secondary charged particles deflected by the other separator, and wherein the secondary charged particle detectors in the first row and the secondary charged particle detectors in the second row are disposed oppositely each other in order not to interfere with each other.

6. An inspection apparatus (4300) having a primary optical system containing an optical axis, a beam source discharging a beam, an aperture plate with a plurality of apertures, a plurality of lenses, and a beam separator so as to irradiate a surface of a sample to be inspected with the beam emitted from the beam source, and a secondary optical system with an optical axis for separating secondary charged particles emitted from the sample from the primary optical system by the beam separator, and delivering and detecting the secondary charged particles in a secondary charged particle detector;

wherein an image of each of the plurality of the apertures is formed by irradiating the aperture plate with the beam from the beam source, and a scanning voltage is applied on an electrostatic deflector so as to have the beam deflect.

7. The inspection apparatus of claim 6, wherein plural sets of the primary optical system and the secondary optical system are disposed in two rows and in plural columns so that paths of the secondary charged particles deflected by the beam separator do not interfere with each other, and wherein the secondary charged particle detectors in the first row and the secondary charged particle detectors in the second row are disposed oppositely each other in order not to interfere with each other.

8. A method for manufacturing devices comprising the steps of:

a. providing a wafer;

b. processing the wafer;

c. detecting a defect on the wafer using the inspection apparatus of claim 6;

d. repeating necessary times of the steps b and c;

e. assembling the wafer into a device.

9. An inspection method for inspecting a sample using a plurality of beams, comprising:

a. emitting charged particle beam from a beam generator;

b. irradiating an aperture plate having a plurality of apertures with the charged particle beam;

c. focusing and scanning the plurality of beams formed by the plurality of the apertures on a sample surface by primary optical systems each of which comprises an optical axis, a lens and a deflector;

d. converging secondary electrons emitted from scanning points on the sample and separating them from the primary optical system by a plurality of separators;

e. forming an enlarged image of the secondary electrons in detecting devices each of which comprises a plurality of detectors through secondary optical systems each of which comprises an optical axis and at least one stage lens;

f. detecting through the plurality of detectors and forming an image;

wherein the primary and the secondary optical columns are disposed in two rows and in plural columns.

10. The inspector method of claim 9, wherein directions of deflection of the separators are set so that the secondary electron detectors in the first row and the secondary electron detectors in the second row are disposed oppositely each other in order not to interfere with each other.

11. An inspection method (4100) comprising:

delivering a plurality of images of apertures onto a sample, said plurality of images of apertures being produced by irradiating a beam emitted from a beam source to an aperture plate having a plurality of apertures; and

separating secondary charged particles generated from the sample from a primary optical system to be delivered into a secondary optical system, and enlarging the secondary charged particles by the secondary optical system to be projected to a surface of a detector by a separator disposed between the objective lens and a neighbor lens of said objective lens at the side of the beam source.

12. An inspection method (4300) comprising:

providing a primary optical system comprising a single beam source for discharging a beam, an aperture plate with a plurality of apertures, a plurality of lenses, and a beam separator, so as to irradiate a surface of a sample to be inspected with the beam emitted from the beam source; and

separating secondary charged particles emitted from the sample from the primary optical system by the beam separator so as to introduce them into a secondary charged particle detector to be detected therein;

wherein the beam from the beam source is irradiated onto the aperture plate to form an image of the plurality of apertures, and a scanning voltage is applied on an electrostatic deflector so as to cause a deflecting operation of the beam.