semi合集-English.pdf - 第1031页
SEMI E141-0705 © SEMI 2005 4 6.3.1.2 rotating polarizer (RP) — Component t hat transm its light wi th a prefer red polariz ation axis (typical ly linearly polarized) and that is rotating during measurement. 6.3.1.3 compe…
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5.1.11 measuring instrument — device intended to be used to make measurements, alone or in conjunction with
supplementary device(s)
1
.
5.1.12 measuring system — complete set of measuring instruments and other equipment assembled to carry out
specified measurements
1
.
5.1.13 metrology — the science of measurement
1
. In semiconductor manufacturing, metrology denotes the science
of measurement to ascertain dimensions, quantity, or capacity; the techniques and procedures for using sensors and
measurement equipment to determine physical and electrical properties in wafer processing
2
.
5.1.14 metrology equipment — any equipment that collects and reports information on specific predetermined sites
or features on a substrate with consistent data structure, or reports general information about the entire substrate
3
.
6 Ellipsometer Equipment
6.1 Ellipsometer Equipment Specification
6.1.1 In the reflection ellipsometric measurement, a light beam with known state of polarization is directed towards
a specular reflecting sample surface. The change in both the amplitude and phase of the oscillating parallel and
perpendicular vector components of the electric field associated with the beam are measured after reflection from
the surface as the complex amplitude reflectance ratio (i.e. a change in the polarization of the light beam occurs).
There are several possible configurations for ellipsometer equipment, which can be described by the arrangement of
modules that comprise the optical components required to perform the ellipsometric measurement. In addition, the
optical components also induce changes in the polarization of the light beam.
6.1.2 For specification of the ellipsometer equipment, it is necessary to describe all modules and optical
components included both in the measuring and in the reflection process from the sample system and their position
within a coordinate system defined by the sample and the light beam. Additionally, information on the number of
wavelengths used for measurement and the method of data acquisition must be provided. The following definitions
are provided for ellipsometer equipment specification.
6.2 Ellipsometer module definition (see Figure 1)
6.2.1 ellipsometer modules — An ellipsometer consists of two modules, the polarizer module and the analyzer
module. The modules comprise the components used to establish and analyze the state of polarization of the incident
and reflected beam, respectively.
6.2.1.1 polarizer module — Arrangement of optical devices that generates a light beam of well-defined known state
of polarization for interacting with the sample system. The polarizer module includes the polarizer device and the
light source and may also include the compensator or modulator.
6.2.1.2 analyzer module — Arrangement of optical devices that allows measurement of the state of polarization of
the light beam after reflection from the sample system. The analyzer module may also include the compensator or
modulator,
and the detector.
6.2.1.3 incident beam — The light beam that passes from the light source through the polarizer module on the
sample surface.
6.2.1.4 reflected beam — The light beam that passes from the sample surface through the analyzer module.
6.2.1.5 plane of incidence — The plane spread by the incident and the reflected beam.
6.2.1.6 angle of incidence (
0
) — Angle between the incident beam and the normal vector of the sample surface.
6.3 Ellipsometer component definition (see Figure 1)
6.3.1 ellipsometer component — An optical device within the ellipsometer that intentionally changes the state of
polarization during the measurement.
6.3.1.1 polarizer (P) — Component that transmits light with a preferred polarization axis (typically linearly
polarized).
2 SEMATECH Official Dictionary, Rev 5.0, SEMATECH Inc., 2004 (Available through www.sematech.org).
3 SEMI International Standards: Compilation of terms. March 2004 (Available through www.semi.org).
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6.3.1.2 rotating polarizer (RP) — Component that transmits light with a preferred polarization axis (typically
linearly polarized) and that is rotating during measurement.
6.3.1.3 compensator (retarder) (C) — Component that can add a phase shift between the components of the electric
field (i.e. the field component parallel to the plane of incidence and perpendicular to the beam direction and the field
component perpendicular to the plane of incidence and to the beam direction, respectively) (see ¶6.4.2.3–¶6.4.2.6).
6.3.1.4 rotating compensator (retarder) (RC) — A rotating component that can add a phase shift between the
components of the electric field (i.e., the field component parallel to the plane of incidence and perpendicular to the
beam direction and the field component perpendicular to the plane of incidence and to the beam direction,
respectively) (see ¶6.4.2.3–¶6.4.2.6).
6.3.1.5 birefringence modulator (BM) — Component that can add a time-modulated phase shift between the
components of the electric field (i.e. the field component parallel to the plane of incidence and perpendicular to the
beam direction and the field component perpendicular to the plane of incidence and to the beam direction,
respectively) (see ¶6.4.2.3–¶6.4.2.6). The photoelastic modulator (PEM) is a component of this type.
NOTE 1: A PEM is an electro-optical modulator made of a suitable birefringent material. By applying an external electric field
to this material, its refractive index changes anisotropically, thus resulting in a phase shift of a transmitting light wave. By driving
the electric field resonantly, the phase of one polarization component of the transmitting light wave will be delayed periodically.
6.3.1.6 analyzer (A) — Component that transmits light with a preferred polarization axis (typically linearly
polarized).
6.3.1.7 rotating analyzer (RA) — Component that transmits light with a preferred polarization axis (typically
linearly polarized) and that is rotating during measurement.
6.3.1.8 sample (S) — Material or layer system to be analyzed. The sample is the reflecting component that changes
the state of polarization in a characteristic manner (typically, light is elliptically polarized after reflection) and that is
to be evaluated.
6.4 Ellipsometer Equipment Definition (see Figure 1)
6.4.1 sequence of ellipsometer components — The first item to be described for the definition of ellipsometer
equipment is the sequence of optical components beginning with the first component in the polarizer module after
the light source and including all the optical components to the analyzer module before the detector element. For this
definition, optical elements that do not intentionally affect the state of light polarization (e.g. the light source, the
detector, or the spectrometer) are not listed.
6.4.1.1 The most commonly applied ellipsometer equipment is listed below.
6.4.1.1.1 P C S A and P S C A — Null Ellipsometer.
6.4.1.1.2 P (C) S RA and P S (C) RA — Rotating Analyzer Ellipsometer (with) without Compensator.
6.4.1.1.3 RP (C) S A and RP S (C) A — Rotating Polarizer Ellipsometer (with) without Compensator.
6.4.1.1.4 P RC S A, P S RC A, and P RC S RC A — Rotating Compensator Ellipsometer.
6.4.1.1.5 P BM S A and P S BM A — Birefringence Modulation Ellipsometer (sample configuration: P PEM S A or
P S PEM A).
6.4.2 position of ellipsometer components — The second item to be described for the definition of ellipsometer
equipment is the position of the optical components within this coordinate system. The ellipsometer setup uses a
coordinate system defined by the sample surface and the light beam (see Figure 1).
6.4.2.1 definition of the optical system of coordinates — The optical system of coordinates is defined by the
electromagnetic field components, described as complex numbers, and the wave vector.
6.4.2.2 wave vector (k
) — The vector indicates the propagation direction of a light beam. The magnitude is given by
|k
| = 2
/
, with
being the wavelength of the light beam. The wave vector of the incident beam is k
i
and that of the
reflected beam is k
r
.
6.4.2.3 electric field vector (E
ip
) — Electric field strength of the incident beam parallel to the plane of incidence and
perpendicular to the wave vector of the incident beam.
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6.4.2.4 electric field vector (E
is
) — Electric field strength of the incident beam perpendicular to the plane of
incidence and perpendicular to the wave vector of the incident beam.
6.4.2.5 electric field vector (E
rp
) — Electric field strength of the reflected beam parallel to the plane of incidence
and perpendicular to the wave vector of the reflected beam.
6.4.2.6 electric field vector (E
rs
) — Electric field strength of the reflected beam perpendicular to the plane of
incidence and perpendicular to the wave vector of the reflected beam.
6.4.2.7 handedness of the coordinate system — The vectors E
ip
, E
is
, and the wave vector k
i
of the incident beam as
well as the vectors E
rp
, E
rs
, and the wave vector k
r
of the reflected beam span a right-handed coordinate system (see
Figure 1).
6.4.2.8 description of the component position — The positions of the ellipsometer components are described by the
following angles, which are specified counterclockwise relative to E
ip
and E
rp
, respectively.
6.4.2.8.1 polarizer azimuth (
P
) — Angle between the plane of incidence and the polarization axis of the light
emerging the polarizer (see Figure 1).
6.4.2.8.2 compensator azimuth (
C
) — Angle between the plane of incidence and the fast axis of the compensator
crystal. If a compensator consists of multiple anisotropic crystals, the axis is defined as the effective axis when the
output is modeled by a single anisotropic crystal (see Figure 1).
6.4.2.8.3 PEM azimuth (
PEM
)
— The PEM azimuth denotes the same angle as
C
for an electronically phase
modulated compensator.
6.4.2.8.4 analyzer azimuth (
A
)
— The analyzer azimuth denotes the angle between the plane of incidence and the
polarization axis of the light emerging the analyzer (see Figure 1).
6.4.3 description of the angle of incidence — The third item to be described for the definition of ellipsometer
equipment is the number of angles of incidence.
6.4.3.1 single-angle ellipsometer (SAE) — With the single-angle ellipsometer, the ellipsometric measurement is
performed at a single angle of incidence.
6.4.3.2 multiple-angle ellipsometer (MAE) — With the multiple-angle ellipsometer, the ellipsometric measurement
is performed at different angles of incidence.
6.4.4 description of measurement wavelength (
— The fourth item to be described for the definition of
ellipsometer equipment is the number of wavelengths used for measurement.
6.4.4.1 single-wavelength ellipsometer (SWE) — With the single-wavelength ellipsometer, one discrete wavelength
is used in the measurement.
6.4.4.2 multiple-wavelengths ellipsometer (MWE) — With the multiple-wavelengths ellipsometer, several discrete
wavelengths are used in the measurement.
6.4.4.3 spectroscopic ellipsometer (SE) — With the spectroscopic ellipsometer many (at least 10) different
wavelengths are used in the measurement.
6.4.5 description of the data acquisition method — The fifth item to be described for the specification of
ellipsometer equipment is the data acquisition method.
6.4.5.1 scanning data acquisition — In scanning data acquisition, the state of polarization is measured wavelength
by wavelength for different positions of one or more optical components.
6.4.5.2 parallel data acquisition — In parallel data acquisition, the state of polarization is measured by
simultaneously varying one or more parameters of the ellipsometer equipment for a defined position of one or more
optical components, e.g. simultaneously measuring the state of polarization for different wavelengths or at different
angles of incidence.
NOTE 2: In the literature, the terms TM (transverse magnetic) and TE (transverse electric) are also used to denote p and s
polarizations, respectively. The TM polarization denotes that the magnetic field vector is perpendicular to the plane of incidence,
while the TE polarization denotes that the electric field vector is perpendicular to the plane of incidence.