N K Technology Ltd

Marc T Aho

Abdul Rahim Forouhi

Thaddeus J Wilson

Guoguang Li

Ray Hebert

Jeff Roberts

Mehdi Balooch

Daniel Tran

Phillip Walsh

Homan Amin

A spatial photomask flipper provides up to four access gates for an unloading of a clamped photomask after its reorientation along a single photomask transfer axis. The clamping frames holding the photomask are secured by a locking control cam that prevents their inadvertent opening in any other but the two main flip orientations. The flipper is part of an automated system including a digital camera and an image recognition algorithm that interpret an arbitrary initial photomask loading orientation from a circumferential photomask identification number. An eventual pellicle on the photomask may be also automatically detected via a pellicle detection sensor. Alternately, the digital camera may be employed for pellicle detection together with a pellicle detection algorithm that processes the digital image for well known components of the pellicle such as the pellicle frame.

Automated spatial flipping apparatus and system for photomasks and photomasks with pellicles

A compact multiple diameter wafer testing device with a footprint of about 33 by 34 inches features on-chuck wafer calibration and integrated cassette-chuck transfer. It includes a five axes wafer handling system, a quick exchange chuck and a fixed through beam sensor fixed. Two of the five axes are provided by an X-Y stage, a third axis is provided by a rotary stage on top of the X-Y stage, a fourth axis belongs to a rotating effector and a fifth axis is provided by motion controlled pin lifters all combined with the X-Y stage. The quick exchange chuck may be easily changed for different wafer diameters and also calibrated by the through beam sensor. The through beam sensor provides on-chuck position calibration of the chucked wafers in conjunction with the X-Y stage and rotary stage. The compact wafer testing device handles wafers between six and twelve inches diameter.

Compact multiple diameters wafer handling system with on-chuck wafer calibration and integrated cassette-chuck transfer

A pellicle correction factor is determined by comparing a first measurement of a reference photomask alone with a second measurement of that reference photomask through a reference pellicle protecting the mask layers of the photomask. A number of pellicle correction factors may be determined for different type pellicles and made accessible in pellicle correction factor lookup table of the system or supplied on a separate data storage medium. Raw Reflectance and/or Transmittance measurement data of a generic photomask through a generic pellicle is consecutively corrected for the measurement distorting effects of that pellicle by applying a matching one of the previously determined pellicle correction factors. The pellicle correction factor is preferably an attenuation signature across a predetermined measurement irradiation spectrum.

System and method for optical photomask inspection through pellicle

A vacuum assisted disc clamping device provides a number of fixture rings preferably concentrically stacked on a fixture body that is moveable in fixture ring stacking direction and actuated by a wedge drive to compensate for varying fixture levels associated with the individual fixture rings and disc standards. Each fixture ring includes a planar flange with a vacuum groove and a central conical portion that rises above the planar flange. The conical portion is defined with a diameter and cone angle such that a disc of corresponding dimensional standard may be readily placed on the fitting fixture ring with the disc bottom being sucked onto the planar flange while the disc hole centers on the conical portion.

Disc clamping device for multiple standard discs

An apparatus and method for examining features of a planar, disk-shaped samples on a stage that holdings the sample and has an X-drive, a Y-drive and a &#x3b8;-drive for rotating the stage about a center of rotation defined in the stage coordinates. The sample is placed on the stage such that the center of the sample is substantially aligned with the center of rotation and a measurement assembly is located above the sample to examine the features optically. A scheduling module coordinates the X-drive, the Y-drive and the &#x3b8;-drive with the measurement assembly such that the sample is examined in an even number n of angular sectors defined by a sector angle &#x398; that is the same for each sector. Specifically, the sector angle &#x398; is defined in terms of n as follows: where n=4and m is an integer, such that a multiple of sector angle &#x398; always includes angles 90&#xb0; and 180&#xb0;.

Apparatus and method for examining a disk-shaped sample on an X-Y-theta stage

An apparatus and method for examining features of a sample with a broadband beam of light obtained from a long-wavelength source that may include two distinct emitters that emit a long-wavelength radiation and a short-wavelength source that emits a short-wavelength radiation. A passage is positioned between the sources and a reflective beam combining optics is provided for shaping the long-wavelength radiation to enter the short-wavelength source via the passage and also for shaping the short-wavelength radiation that exits through the passage and propagates toward the long-wavelength source. The reflective beam combining optics shape the short-wavelength radiation such that it re-enters the short-wavelength source via the passage and is combined with the long-wavelength radiation into the broadband beam that exits the short-wavelength source. A beam steering optics projects the broadband beam to a spot on the sample, and a scattered broadband radiation from the spot is intercepted and shaped to a broadband signal beam, which is passed through a sampling pinhole that passes a test portion of it on to a detector for optical examination; the test portion that is passed can correspond to a center portion of the spot.

System and method for high intensity small spot optical metrology

A system uses reflectance spectrophotometry to characterize a sample having any number of structures. The system uses toroidal mirrors that are shaped in such a way that the angle of reflectance off of the target is small. The small angle of reflectance may allow for simplification of calculations and can result in a faster processing time. In addition, a more accurate measurement can be achieved when the reflected beam is close to normal.

Spectrophotometric system with reduced angle of incidence

An apparatus and method for optically characterizing the reflection and transmission properties of a sample with a beam of light having a small diameter on a surface of the sample over a broadband of wavelengths, from 190 nm to 1100 nm. Reflective optical components, including off-axis parabolic mirrors with a collimated incident or reflected broadband beam of light, minimize non-chromatic aberration. Angles of incidence and reflection from optical components and the sample are kept substantially near normal to the optical components and the sample to minimize changes in the polarization of the beam of light. The apparatus and method further disclose an optical light path that can be focused by adjusting the position of an off-axis parabolic mirror and a planar mirror.

Apparatus and method for optical characterization of a sample over a broadband of wavelengths while minimizing polarization changes

An apparatus and method for optically characterizing the reflection and transmission properties of a sample with a beam of light having a small diameter on a surface of the sample over a broadband of wavelengths, from 190 nm to 1100 nm. Reflective optical components, including off-axis parabolic mirrors with a collimated incident or reflected broadband beam of light, minimize non-chromatic aberration. The apparatus and method further disclose an optical light path that can be focused by adjusting the position of an off-axis parabolic mirror and a planar mirror.

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Mountain View, CA, United States of America

Marc T Aho