Particle detection device, lithographic apparatus and device manufacturing method
First Claim
1. A particle detection system configured to detect a particle on a surface of an object, the system comprising:
- a first radiation source configured to generate a beam of radiation having a first wavelength, the beam of radiation being directed to a detection area at the surface of the object;
a radiation detector system configured to output a plurality of detector signals corresponding to an intensity of radiation received from the detection area incident on the radiation detector system; and
a detection circuit coupled to the radiation detector system and configured to determine from the plurality of detector signals whether a particle is present on the surface of the object, wherein presence of a particle is determined by resolving a signal from a ghost particle relative to a signal from the particle.
2 Assignments
0 Petitions
Accused Products
Abstract
To enable differentiation between a particle and a ghost particle, a detector system resolves radiation from a ghost particle from radiation from an actual particle. The detector system outputs at least two detector signals corresponding to intensities of radiation being incident on different parts of the detector system or the detector system outputs at least two detector signals corresponding to intensities of radiation with different wavelengths being incident on the detector system. If radiation is received from a ghost particle, not each of the at least two detector signals has a level above a predetermined threshold level, whereas radiation received from a particle results in the signals having substantially a same level above a threshold level. The detector system may include a radiation detector device configured to generate the first detector signal in response to radiation incident on at least one predetermined part of the radiation detector device and a radiation blocking assembly configured to prevent radiation not originating from a particle from being incident on the predetermined part of the detector device.
-
Citations
38 Claims
-
1. A particle detection system configured to detect a particle on a surface of an object, the system comprising:
-
a first radiation source configured to generate a beam of radiation having a first wavelength, the beam of radiation being directed to a detection area at the surface of the object;
a radiation detector system configured to output a plurality of detector signals corresponding to an intensity of radiation received from the detection area incident on the radiation detector system; and
a detection circuit coupled to the radiation detector system and configured to determine from the plurality of detector signals whether a particle is present on the surface of the object, wherein presence of a particle is determined by resolving a signal from a ghost particle relative to a signal from the particle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A lithographic apparatus comprising:
-
an illumination system configured to condition a beam of radiation;
a support structure configured to support a patterning device, the patterning device serving to impart the beam of radiation with a pattern in its cross-section;
a substrate table configured to hold a substrate;
a projection system configured to project the patterned beam onto a target portion of the substrate, and a particle detection system configured to detect a particle in a detection area at a surface of an object, wherein presence of a particle is determined by spatially resolving a signal from a ghost particle from a signal from the particle. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
-
-
33. A device manufacturing method comprising:
-
projecting a patterned beam of radiation onto a target portion of a substrate, and detecting a particle on a surface of an object with a particle detection system, wherein said particle detection system comprises a detection circuit, which is configured to compare a plurality of detector signals with a predetermined threshold level, and to indicate that the particle is present on the surface of the object, when said plurality of detector signals has a level above said threshold level. - View Dependent Claims (34)
-
-
35. A device manufacturing method comprising:
-
projecting a patterned beam of radiation onto a target portion of a substrate, and detecting a particle on a surface of an object with a particle detection system, wherein the particle detection system comprises a radiation detector device for generating the first detector signal in response to radiation incident on at least one predetermined part of the radiation detector device; and
a radiation blocking assembly for preventing radiation not originating from a detection range around the surface of the object from being incident on the predetermined part of the detector device. - View Dependent Claims (36)
-
-
37. A device manufacturing method comprising:
-
projecting a patterned beam of radiation onto a target portion of a substrate, and detecting a particle on a surface of an object, said detecting including;
providing a beam of radiation onto the surface of said object, detecting the beam of radiation redirected by said particle and/or said object;
outputting a plurality of signals corresponding to an intensity of the detected beam of radiation; and
comparing the plurality of signals with a predetermined threshold level to determine whether a particle is present on the surface of said object.
-
-
38. A device manufacturing method comprising:
-
projecting a patterned beam of radiation onto a target portion of a substrate, and detecting a particle on a surface of an object, said detecting including;
providing a beam of radiation onto the surface of said object, detecting the beam of radiation redirected by said particle and/or said object;
directing a beam of radiation originating from within a detection range around the surface of the object on a predetermined part of a radiation detection device;
preventing radiation not originating from within a detection range around the surface of the object from being incident on the predetermined part of a radiation detection device; and
determining whether a particle is present on the surface of said object based on a detector signal corresponding to an intensity of the detected beam of radiation incident on the predetermined part of the radiation detection device.
-
Specification