摘要:
Embodiments of the invention relate to a system for contactless cleaning of an object surface, a lithographic apparatus including the system, and a method of manufacturing a device. The system may include a He plasma source contained in a chamber and a control unit constructed to modify plasma parameters in use, such as the electron energy distribution of the plasma for causing an increase in formation of He metastables without modifying operational parameters of the plasma source. The control unit may include an electrical biasing unit constructed to apply a positive bias voltage to the object, for attracting free electrons from the plasma. The system may include a supplementary gas source, which may be either pre-mixed with He or be supplied from a further gas source. The supplementary gas may be selected based on a pre-knowledge on a type of particles to be expected on the surface of the object.
摘要:
A lithographic apparatus includes an illumination system configured to condition a beam of radiation, and a support structure configured to support a patterning device. The patterning device is configured to impart a pattern to the beam of radiation. The apparatus includes a patterning device cleaning system configured to provide an electrostatic force to contaminant particles that are on the patterning device and that are electrically charged by the beam of radiation, in order to remove the contaminant particles from the patterning device.
摘要:
An optical assembly is mounted in a projection exposure apparatus (101) for EUV microlithography and includes at least one vacuum chamber (70, 71, 68a), at least one optical element (6, 7; 65, 66; 63) arranged in the vacuum chamber (70, 71, 68a), the optical element (6, 7; 65, 66; 63) having an optical surface (18) arranged to be impinged upon by a useful beam bundle (3) of the projection exposure apparatus (101), and a cleaning device (72) configured to clean the optical surface (18). The cleaning device (72) is configured to perform particle cleaning of the optical surface (18) at a gas pressure within the vacuum chamber (70,71, 68a) which is higher than a vacuum pressure (po) for performing an exposure operation with the projection exposure apparatus (101). As a result, optical elements having respective optical surfaces arranged to be impinged upon by a useful beam bundle can be cleaned reliably of foreign particles.
摘要:
An optical assembly is mounted in a projection exposure apparatus (101) for EUV microlithography and includes at least one vacuum chamber (70, 71, 68a), at least one optical element (6, 7; 65, 66; 63) arranged in the vacuum chamber (70, 71, 68a), the optical element (6, 7; 65, 66; 63) having an optical surface (18) arranged to be impinged upon by a useful beam bundle (3) of the projection exposure apparatus (101), and a cleaning device (72) configured to clean the optical surface (18). The cleaning device (72) is configured to perform particle cleaning of the optical surface (18) at a gas pressure within the vacuum chamber (70,71, 68a) which is higher than a vacuum pressure (po) for performing an exposure operation with the projection exposure apparatus (101). As a result, optical elements having respective optical surfaces arranged to be impinged upon by a useful beam bundle can be cleaned reliably of foreign particles.
摘要:
A contaminant trap is used in an EUV radiation source apparatus. An EUV radiation beam is generated and focused through a low pressure gaseous atmosphere into a virtual source point. The EUV radiation creates a plasma in the low pressure hydrogen atmosphere through which it passes. A contaminant trap including electrodes is located in or around radiation beam as it approaches the virtual source point. A DC biasing source is connected to the electrodes to create an electric field oriented to deflect out of the beam path contaminant particles that have been negatively charged by the plasma. Additional RF electrodes and/or an ionizer enhance the plasma to increase the charging of the particles. The deflecting electrodes can be operated with RF bias for a short time, to ensure dissipation of the enhanced plasma.
摘要:
Methods and systems for inspection of an object include the use of spectroscopic techniques for the detection of unwanted particles on an object's surface, based on the different responses of the unwanted particles as compared with the object to be inspected due to their different materials. Time resolved spectroscopy and/or energy resolved spectroscopy of secondary photon emission from the surface of the object can be used to obtain Raman and photoluminescence spectra. The objects to be inspected can for example be a patterning device as used in a lithographic process, for example a reticle, in which case the presence of metal, metal oxide or organic particles can be detected, for example. The methods and apparatus are highly sensitive, for example, being able to detect small particles (sub 100 nm, particularly sub 50 nm) on the patterned side of an EUV reticle.
摘要:
Methods and systems for inspection of an object include the use of spectroscopic techniques for the detection of unwanted particles on an object's surface, based on the different responses of the unwanted particles as compared with the object to be inspected due to their different materials. Time resolved spectroscopy and/or energy resolved spectroscopy of secondary photon emission from the surface of the object can be used to obtain Raman and photoluminescence spectra. The objects to be inspected can for example be a patterning device as used in a lithographic process, for example a reticle, in which case the presence of metal, metal oxide or organic particles can be detected, for example. The methods and apparatus are highly sensitive, for example, being able to detect small particles (sub 100 nm, particularly sub 50 nm) on the patterned side of an EUV reticle.
摘要:
In an aspect, an inspection method for detecting the presence or absence of a defect on an object, the object comprising a recess having a physical depth, is disclosed. The method includes directing radiation at the object, the radiation having a wavelength that is substantially equal to twice an optical depth of the recess, detecting radiation that is re-directed by the object or a defect on the object, and determining the presence or absence of a defect from the re-directed radiation.
摘要:
An EUV lithography reticle is inspected to detect contaminant particles. The inspection apparatus comprises illumination optics with primary radiation. An imaging optical system with plural branches is arranged to form and detect a plurality of images, each branch having an image sensor and forming its image with a different portion of radiation received from the illuminated article. A processor combines information from the detected images to report on the presence and location of contaminant particles. In one or more branches the primary radiation is filtered out, so that the detected image is formed using only secondary radiation emitted by contaminant material in response to the primary radiation. In a dark field imaging branch using the scattered primary radiation, a spatial filter blocks spatial frequency components associated with periodic features of the article under inspection, to allow detection of particles which cannot be detected by secondary radiation.
摘要:
A system for removing contaminant particles from the path of the beam of EUV radiation is provided in which at least a first AC voltage is provided to a pair of electrodes on opposite sides of the path of the beam of EUV radiation as a first stage of a regime of voltages and, as a second stage of the regime of voltages, a DC voltage is provided to the electrodes.