Skip to Content
Find More Like This
Return to Search

Wafer Characteristics via Reflectometry and Wafer Processing Apparatus and Method

National Renewable Energy Laboratory

Contact NREL About This Technology

Technology Marketing Summary

Wafers find a variety of uses in the semiconductor, solar energy and other industries. Wafer quality often depends on variables such as thickness and surface characteristics. Depending on end use, poor quality wafers may have uneven thickness or uneven surface characteristics; whereas, higher quality wafers may have substantially uniform thickness and substantially uniform surface characteristics. In the semiconductor industry, where wafers are used as a substrate, wafer quality can crucially influence mechanical and/or electronic yield of wafer-based semiconductor circuits.

Wafer thickness can affect mechanical, electronic and optical behavior or performance. With respect to mechanical performance, increased thickness can minimize detrimental effects of fabrication or use associated stresses. With respect to electronic and optical performance, wafer thickness is often an important variable. Further, wafer thickness is often defined by distance between an upper wafer surface and a lower wafer surface. Characteristics of one or both of these surfaces generally affect electronic and optical performance.

 

Description

Engineers at the National Renewable Energy Laboratory (NREL) have developed a system which includes a measuring device to acquire non-contact thickness measurements of a wafer and a laser beam to cut the wafer at a rate based at least in part on one or more thickness measurements. This is done by illuminating a substrate with radiation, measuring at least some radiation reflected from the substrate, determining one or more cutting parameters based at least in part on the measured radiation and cutting the substrate using the one or more cutting parameters.

 

Benefits
  • Higher mechanical, electronic and optical performance
  • Reduced time, equipment and measurement costs

 

Applications and Industries
  • Semiconductors
  • Solar energy
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Date
Patent 7,815,862
Patent
7,815,862
Wafer characteristics via reflectometry
Various exemplary methods (800, 900, 1000, 1100) are directed to determining wafer thickness and/or wafer surface characteristics. An exemplary method (900) includes measuring reflectance of a wafer and comparing the measured reflectance to a calculated reflectance or a reflectance stored in a database. Another exemplary method (800) includes positioning a wafer on a reflecting support to extend a reflectance range. An exemplary device (200) has an input (210), analysis modules (222-228) and optionally a database (230). Various exemplary reflectometer chambers (1300, 1400) include radiation sources positioned at a first altitudinal angle (1308, 1408) and at a second altitudinal angle (1312, 1412). An exemplary method includes selecting radiation sources positioned at various altitudinal angles. An exemplary element (1650, 1850) includes a first aperture (1654, 1854) and a second aperture (1658, 1858) that can transmit reflected radiation to a fiber and an imager, respectfully.
National Renewable Energy Laboratory 10/19/2010
Issued
Patent 7,238,912
Patent
7,238,912
Wafer characteristics via reflectometry and wafer processing apparatus and method
An exemplary system includes a measuring device to acquire non-contact thickness measurements of a wafer and a laser beam to cut the wafer at a rate based at least in part on one or more thicknesses measurements. An exemplary method includes illuminating a substrate with radiation, measuring at least some radiation reflected from the substrate, determining one or more cutting parameters based at least in part on the measured radiation and cutting the substrate using the one or more cutting parameters. Various other exemplary methods, devices, systems, etc., are also disclosed.
National Renewable Energy Laboratory 07/03/2007
Issued
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
NREL ROIs 02-15, 03-22DevelopmentAvailable03/14/201603/21/2016

Contact NREL About This Technology

To: Erin Beaumont<erin.beaumont@nrel.gov>