semi合集-English.pdf - 第7191页
SEMI INTERNATIONAL STANDARDS SILICON MATERIALS & PROCESS CONTROL Semiconductor Equipment and Materials International
SEMI S24-0705 © SEMI 2005 10
NOTICE: SEMI makes no warranties or representations as to the suitability of the standards set forth herein for any
particular application. The determination of the suitability of the standard is solely the responsibility of the user.
Users are cautioned to refer to manufacturer's instructions, product labels, product data sheets, and other relevant
literature, respecting any materials or equipment mentioned herein. These standards are subject to change without
notice.
By publication of this standard, Semiconductor Equipment and Materials International (SEMI) takes no position
respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this
standard. Users of this standard are expressly advised that determination of any such patent rights or copyrights, and
the risk of infringement of such rights are entirely their own responsibility.
Copyright by SEMI® (Semiconductor Equipment and Materials
International), 3081 Zanker Road, San Jose, CA 95134. Reproduction of
the contents in whole or in part is forbidden without express written
consent of SEMI.
SEMI INTERNATIONAL STANDARDS
SILICON MATERIALS & PROCESS CONTROL
Semiconductor Equipment and Materials International
SEMI ME1392-0305 © SEMI 2003, 2005 1
SEMI ME1392-0305
GUIDE FOR ANGLE RESOLVED OPTICAL SCATTER
MEASUREMENTS ON SPECULAR OR DIFFUSE SURFACES
This guide was technically approved by the Global Silicon Wafer Committee and is the direct responsibility
of the North American Silicon Wafer Committee. Current edition approved for publication by the North
American Regional Standards Committee on December 10, 2004. Initially available at
www.semi.org
January 2005; to be published March 2005. Original edition published by ASTM International as ASTM E
1392-90. Last previous edition SEMI ME 1392-96 (Reapproved 2002).
1 Purpose
1.1 The microroughness and contamination due to particulates and films on silicon wafers are interrogated with
varying forms of light scattering techniques. The angular distribution of light scattered by semiconductor surfaces is
a generalized basis for most scanning surface inspection systems and as such may be used to cross-correlate various
tools.
1.2 The angular distribution of scatter from optically smooth surfaces, such as polished silicon wafers, can be used
to calculate surface parameters or reveal surface characteristics. For example, the total scatter found by integrating
the bidirectional reflectance distribution function (BRDF) over the hemisphere can be related to surface roughness.
The amount of scatter at a given scatter angle can be associated with a specific surface spatial frequency.
1.3 The angular distribution of scatter is a general property of surfaces that may have direct consequences. Scatter
from mirrors and other components in an optical system can be the limiting factor in resolution or optical signal to
noise level. Scatter can be an important design parameter for telescopes. Scatter measurements are crucial to
correct operation of ring laser gyros. Scatter from a painted surface, such as on automobiles, can influence sales
appeal.
2 Scope
2.1 This guide explains a procedure for the determination of the amount and angular distribution of optical scatter
from an opaque surface. In particular it focuses on measurement of the BRDF, which is a convenient and well
accepted means of expressing optical scatter levels for many purposes.
1
,2
Additional data presentation formats
described in Related Information 1 have advantages for certain applications. Surface parameters can be calculated
from optical scatter data when assumptions are made about model relationships. Some of these extrapolated
parameters are described in Related Information 2.
2.2 Optical scatter from an opaque surface results from surface topography, surface contamination, and subsurface
effects. It is the user’s responsibility to be certain that measured scatter levels are ascribed to the correct
mechanism. Scatter from small amounts of contamination can easily dominate the scatter from a smooth surface.
Likewise, subsurface effects may play a more important scatter role than typically realized when surfaces are
superpolished.
2.3 This guide does not provide a method to extrapolate data for one wavelength from data for any other
wavelength. Data taken at particular incident and scatter directions are not extrapolated to other directions. In other
words, no wavelength or angle scaling is to be inferred from this guide. Normally the user must make
measurements at the wavelengths and angles of interest.
2.4 This guide applies only to BRDF measurements on opaque samples. It does not apply to scatter from
translucent or transparent materials. There are subtle complications which affect measurement of translucent or
transparent materials that are best addressed in separate standards (see, for example, ASTM Practice E 167 and
ASTM Guide E 179).
2.5 The wavelengths for which this guide applies include the ultraviolet, visible, and infrared regions. Difficulty in
obtaining appropriate sources, detectors, and low scatter optics complicate its practical application at wavelengths
less than about 0.25 m. Diffraction effects that start to become important for wavelengths greater than 15 m
1 Nicodemus, Fred E., “Directional Reflectance and Emissivity of an Opaque Object,” Applied Optics 4, 767 (1965).
2 Nicodemus, F. E., Richmond, J. C., and Hsia, J. J., “Geometrical Considerations and Nomenclature for Reflectance,” NBS Monograph 160,
1977.