A wafer edge grinding or polishing machine is provided with a pair of chucks for engaging a wafer therebetween, a fixed reference surface and a sensor which is movable with a movable chuck. Measurements are made by the sensor relative to the fixed reference plane when the movable chuck is in engagement with the opposite chuck without a wafer therebetween in order to obtain a standard measurement value. With a wafer between the chucks, the sensor obtains an actual measurement value relative to the fixed reference surface. A calculator determines the difference between the standard and actual measurements values and displays the difference as the thickness of the wafer. Multiple sensors may be used to obtain multiples readings which are averaged by the calculator to obtain a thickness measurement.
Stephen Chou - Princeton NJ, US Linshu Kong - Plainsboro NJ, US Colby Steere - Parsippany NJ, US Mingtao (Gary) Li - Boise ID, US Hua Tan - South Bound Brook NJ, US Lin Hu - Livingston NJ, US
Apparatus for double-sided imprint lithography of an apertured substrate comprises a pair of correspondingly apertured molds, a support for an assembly of the substrate and molds, and an alignment mechanism with radially movable elements for aligning the apertures of the molds and the substrate. The movable elements can be at least partially disposed in a spindle and can be removed radially outward by a conically tapered drive rod. Opposing surfaces of the substrate can then be imprinted in registration at the same time, preferably by fluid pressure imprint lithography.
Align-Transfer-Imprint System For Imprint Lithogrphy
Hua Tan - Princeton Junction NJ, US Wei Zhang - Plainsboro NJ, US He Gao - Plainsboro NJ, US Linshu Kong - Plainsboro NJ, US Lin Hu - Livingston NJ, US Colby Steere - Parsippany NJ, US Stephen Y. Chou - Princeton NJ, US
International Classification:
H01L 21/304
US Classification:
425112
Abstract:
An imprint system for imprint lithography comprises an alignment subsystem and an imprint subsystem. The mask (mold) and the wafer for imprinting (substrate) are align on the alignment subsystem and contacted to each other to form a mask/wafer set. The mask/wafer set is then transferred onto the imprint subsystem while alignment is maintained. The mask/wafer set is then imprinted on the imprint subsystem. During transfer, the mask/wafer set can be held in alignment by surface. The surface adhesion can be enhanced by local pressing, local heating, or both. Alternatively, the mask/wafer set can be held in alignment by clamping. Advantageously, the imprinting is effected by fluid pressure imprinting.
A wafer scrubbing machine is provided with a network of wafer holders which can be moved from a retracted position adjacent each other at a wafer receiving station to an expanded position spaced apart from each within a scrubbing station. The wafers are picked up simultaneously by pairs of depending arms in the scrubbing station and passed between pairs of rotating brushes for cleaning purposes. A common drive wheel is provided to rotate the wafers simultaneously during scrubbing between the brushes. A second network of wafer holders is provided to receive the scrubbed wafers in the scrubbing station and to move into a retracted position within a delivery station for transfer of the cleaned wafers into a cassette for subsequent processing. Two sets of networks may be provided on a common rotatable assembly in order to accommodate two different sizes of delivered wafers.