Ultratech, Inc.

California Institute of Technology

David M Owen

Ares J Rosakis

Andrew M Hawryluk

David A Boyd

Sean Olson

Stephen Gledden

Systems and methods of characterizing wafer shape using coherent gradient sensing (CGS) interferometry are disclosed. The method includes measuring at least 3&#xd7;10data points on a wafer surface using a CGS system to obtain a topography map of the wafer surface. The data are collected on a wafer for pre-processing and post-processing of the wafer, and the difference calculated to obtain a measurement of the effect of the process on wafer surface shape. The process steps for processing the same wafer or subsequent wafers are controlled based on measured process-induced change in the wafer surface shape in order to improve the quality of the wafer processing.

Systems and methods of characterizing process-induced wafer shape for process control using CGS interferometry

Methods of characterizing semiconductor light-emitting devices (LEDs) based on product wafer characteristics are disclosed. The methods include measuring at least one product wafer characteristic, such curvature or device layer stress. The method also includes establishing a relationship between the at least one characteristic and the emission wavelengths of the LED dies formed from the product wafer. The relationship allows for predicting the emission wavelength of LED structures formed in the device layer of similarly formed product wafers. This in turn can be used to characterize the product wafers and in particular the LED structures formed thereon, and to perform process control in high-volume LED manufacturing.

Methods of characterizing semiconductor light-emitting devices based on product wafer characteristics

Provided are methods to be carried out prior to, while, and/or after performing a photolithographic process to a wafer that involve wafer misalignment assessment. The method involves obtaining curvature and/or deformation information of a surface of the wafer over a plurality of locations so as to obtain a curvature map of the wafer. The curvature map is processed to obtain a stress map of the wafer. The stress map is used to determine displacement of a layer of the wafer. The displacement information is used to determine a degree of misalignment in the photolithographic process.

Determination of lithography misalignment based on curvature and stress mapping data of substrates

Techniques and systems for using optical interferometers to obtain full-field optical measurements of surfaces, such as surfaces of flat panels, patterned surfaces of wafers and substrates. Applications of various shearing interferometers for measuring surfaces are described.

Full-field optical measurements of surface properties of panels, substrates and wafers

Systems and techniques for integrating an optical coherent gradient sensing (CGS) module and another optical sensing module to simultaneously measure the curvature and another property of a specularly reflective surface.

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Redondo Beach, CA, United States of America

David M Owen