Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
  • G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
  • G01N23/2204—Specimen supports therefor; Sample conveying means therefore
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B21/00—Microscopes
  • G02B21/32—Micromanipulators structurally combined with microscopes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
  • H01J2237/30—Electron or ion beam tubes for processing objects
  • H01J2237/317—Processing objects on a microscale
  • H01J2237/3174—Etching microareas
  • H01J2237/31745—Etching microareas for preparing specimen to be viewed in microscopes or analyzed in microanalysers

Definitions

• This disclosure describes a novel method for removing a particle of interest from a sample surface, transporting that particle to a second sample surface with a controlled X-ray or Auger background, and performing electron beam-induced X-ray analysis or Auger electron analysis there, using any of the methods discussed above. This eliminates the requirement that the analyzing technique have high spatial resolution, although a technique with high spatial resolution, such as EDS analysis in the SEM and SAM analysis, is generally preferred.
• XPS X-ray Photoelectron Spectroscopy
• XRF X-ray Fluorescence analysis
• the proposed method for particle manipulation and EDS X-ray analysis can be done in-line on existing wafer-manufacturing tools.
• An in-line procedure using existing manufacturing and inspection tools represents a significant reduction in cycle time for contamination removal.
• SEM is a routine method for wafer inspection, and analytical methods using the electron beam in an SEM system provide a substantial throughput advantage over the off-line strategies.
• FIG. 1 shows the steps of attaching a particle to a micro-manipulator probe and removing the particle to a second surface for analysis.
• Figure 2 shows three other methods of attaching a particle to a micro- manipulator probe.
• Figure 3 shows the process of modifying electrostatic forces by bombardment with polarizable molecules.
• the method comprises positioning a micro-manipulator probe near the particle; attaching the particle to the probe; moving the probe and the attached particle away from the first sample surface; positioning the particle on a second sample surface; and, analyzing the composition of the particle on the second sample surface by energy- dispersive X-ray analysis, Auger microprobe analysis or any other suitable analytical technique.
• the second surface has a reduced or non-interfering background signal during analysis, relative to the background signal of the first surface. (We call such a reduced or non-interfering background signal a "controlled" background signal in the claims.) We also disclose methods for adjusting the electrostatic forces and DC potentials between the probe, the particle, and the sample surfaces to effect removal of the particle, and its transfer and relocation to the second sample surface.
• Adjustment of the electrostatic forces may include locally adjusting the energy or intensity (intensity means beam current for electron and ion beams) of an electron beam, ion beam or photon beam incident on the individual components of the sample system, which includes the probe tip, particle and first sample surface, to create an electrostatic attraction between the particle and probe tip, or an electrostatic repulsion between the particle and the first sample surface. This procedure is reversed to transfer the particle from the probe tip to the second sample surface.
• the second sample surface may be the probe tip itself. In this case the probe tip is composed of a controlled background material.
• IB through ID show, respectively, the irradiation of the particle (100) and first sample surface (110) by photons or a charged-particle beam (140) to cause attachment of the particle (100) to the probe (120), the removal of the probe (120) and attached particle (100) from the first sample surface (110), and the deposition of the particle (100) on a second sample surface (150) for analysis.
• the drawings are not to scale. Attaching the particle to the probe Strong electrostatic forces exist on particles in a vacuum. The presence of static charges on the particle (100) and the probe (120) leads to the creation of image charges on the opposite surfaces. These image charges create forces that are proportional to the area exposed and inversely proportional to the distance between the objects.
• Reducing or increasing the exposed area will therefore either reduce or increase the force acting on the particle (100), and the resultant adhesion between probe (120) and particle (100).
• This can be used as a straightforward method to remove particles of interest from the sample, using either a conducting or insulating probe (120).
• Conducting probes allow more versatility through the introduction of static or time varying voltages or electrostatic charges to the probe (120) from a voltage or electrostatic charge source (130), as shown generally in Fig. 1A.
• the shape of the tip of the probe (120) will also influence the electric fields at the tip. Static electric charges on a blunt tip will exert stronger influence on a particle in line with the tip than a sharply pointed tip.
• FIG. 5D shows a wrinkled surface (220) on an insulating second sample surface (150).
• the wrinkled surface (220) allows an increased area of contact between the particle (100) and the second sample surface (150), thus changing the electrostatic forces between them.
• Fig. 5E shows an electrified pattern (230) written on the second sample surface (150) by the charged-particle beam (140). The electrostatic field of such a pattern can assist in the transfer of the particle from the probe (120) to the second sample surface (150).
• Figure 5F shows a porous second sample surface (150) having holes or pores (290).
• Such surfaces may be micro-pore filters, such as the MICROPORE series of filters manufactured by 3M Corporation of St.
• the methods described in the previous section for adjusting the electrostatic forces in the particle-probe-sample surface system for attaching the particle (100) to the probe (120) can also be used to remove the particle (100) from the probe (120) and attach it to the second sample surface (150).
• the voltage or charge source (130) may generate a rapid transient or resonant phenomenon, for example, by rapidly switching stored negative charge from a capacitor through the probe (120), or by a time- varying voltage, such as a square wave or pulse, applied to the probe (120) from the source (130).
• Analyzing the particle X-ray analysis or Auger analysis can be performed with the particle (100) directly on the probe tip (125), as shown in Fig. 6.

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Analysing Materials By The Use Of Radiation (AREA)

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• 2004
  • 2004-06-08 CN CNA2004800379489A patent/CN1977159A/zh active Pending
  • 2004-06-08 CA CA002543396A patent/CA2543396A1/en not_active Abandoned
  • 2004-06-08 WO PCT/US2004/018206 patent/WO2005123227A2/en not_active Application Discontinuation
  • 2004-06-08 EP EP04754729A patent/EP1754049A2/de not_active Withdrawn

Non-Patent Citations (1)

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