SEMI
M52 requires the use of certified reference materials (CRMs) for calibration of
scanning surface inspection systems (SSISs). The calibration method is defined
in SEMI M53. This Test Method provides the procedure to determine whether a
specific particle deposition system, using a differential mobility analyzer
(DMA), can produce the required CRMs.
Both
organizations producing depositions internally for in-house use and companies
manufacturing depositions for sale can apply this Test Method to ensure that
their particle deposition systems provide depositions that meet the
requirements of SEMI M52.
Scope
This
Test Method covers determination of the deposition peak diameter and the
associated expanded relative combined peak diameter uncertainty produced by a
particle deposition system and its associated deposition procedures for
comparison to the 3% requirement of SEMI M52.
This
Test Method also covers determination of the ability of the deposition system
to produce depositions with diameter distributions that are less than 5% full
width at half maximum (FWHM) as required by SEMI M52 even when using a particle
source with a much wider distribution.
These
tests require that the deposition system employ a DMA (or an equivalent
programmable filtering system) to accomplish both peak diameter determination
and narrowing of particle source distributions (see Related Information 1).
This
Test Method covers determination of repeatability over a period of one week.
Tests can be repeated periodically to determine long term stability. Long term
stability of most DMA-based particle deposition systems is believed to be on
the order of a year or more, but it is recommended that the tests be repeated
on an annual basis or whenever the instrument appears to be out of control.
This
Test Method requires the use of three different kinds of particle distributions
with specified characteristics and wafers that have surface characteristics
adequate to allow detection of the smallest particles utilized with a capture
rate of greater than 95%.
Referenced SEMI Standards
SEMI M50 — Test
Method for Determining Capture Rate and False Count Rate for Surface Scanning
Inspection Systems by the Overlay Method
SEMI M52 — Guide
for Specifying Scanning Surface Inspection Systems for Silicon Wafers for the 130
nm to 11 nm Technology Generations
SEMI M53 —
Practice for Calibrating Scanning Surface Inspection Systems Using Certified
Depositions of Monodisperse Reference Spheres on Unpatterned Semiconductor
Wafer Surfaces
SEMI M59 —
Terminology for Silicon Technology
SEMI ME1392 —
Guide for Angle Resolved Optical Scatter Measurements on Specular or Diffuse
Surfaces
SEMI MF1811 —
Guide for Estimating the Power Spectral Density Function and Related Finish
Parameters from Surface Profile Data