U.S. patent application number 13/757543 was filed with the patent office on 2014-08-07 for apparatus of analyzing a sample and a method for the same.
The applicant listed for this patent is Taiwan Semiconductor Manufacturing Company, Ltd.. Invention is credited to Yuan-Chih Chu, Yen-Kai Huang.
Application Number | 20140223616 13/757543 |
Document ID | / |
Family ID | 51260519 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140223616 |
Kind Code |
A1 |
Huang; Yen-Kai ; et
al. |
August 7, 2014 |
Apparatus of Analyzing a Sample and a Method for the Same
Abstract
The apparatus includes a probe tip configured to scan a
substrate having a defect to attach the defect on the probe tip
while scanning the substrate, a cantilever configured to integrate
a holder holding at least one probe tip, a stage configured to
secure the substrate, an electromagnetic radiation source
configured to generate the electromagnetic radiation beam, and an
electromagnetic radiation detector configured to receive the first
electromagnetic radiation signal and the second electromagnetic
radiation signal. A first electromagnetic radiation signal is
generated while an electromagnetic radiation beam focuses on the
probe tip. A second electromagnetic radiation signal is generated
while the electromagnetic radiation beam focuses on the sample
attached on the probe tip. A chemical analysis of the sample is
executed by comparing a difference between the first
electromagnetic radiation signal and the second electromagnetic
radiation signal.
Inventors: |
Huang; Yen-Kai; (Hsinchu
City, TW) ; Chu; Yuan-Chih; (New Taipei City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ltd.; Taiwan Semiconductor Manufacturing Company, |
|
|
US |
|
|
Family ID: |
51260519 |
Appl. No.: |
13/757543 |
Filed: |
February 1, 2013 |
Current U.S.
Class: |
850/9 |
Current CPC
Class: |
G01N 21/94 20130101;
G01N 21/35 20130101; G01N 23/2251 20130101; G01N 21/9501 20130101;
G01N 2021/3595 20130101; H01J 37/20 20130101; G01N 2223/611
20130101 |
Class at
Publication: |
850/9 |
International
Class: |
G01Q 30/02 20060101
G01Q030/02 |
Claims
1. An apparatus comprising: a stage for securing a substrate; a
probe tip configured to be positioned in a first location near the
substrate, by which the probe tip can secure a sample from the
substrate, and in a second location, different from the first
location, by which the secured sample can be exposed to a radiation
source; the radiation source configured to generate and direct the
electromagnetic radiation beam onto the secured sample; and an
electromagnetic radiation detector configured to receive the
electromagnetic radiation beam after engaging with the sample.
2. The apparatus of claim 1, further comprising a computer
configured to move the probe tip between the first and second
locations.
3. The apparatus of claim 1, further comprising: a cantilever
includes a motor for rotating the probe tip between the first and
second locations.
4. The apparatus of claim 1, wherein the probe tip includes a
metal, a metal compound or a carbon-based material.
5. The apparatus of claim 1, wherein the radiation source includes
a light source, an ion source, or an electron source.
6. The apparatus of claim 5, wherein the electromagnetic radiation
beam includes a light beam, an ion beam, or an electron beam.
7. The apparatus of claim 6, wherein the electromagnetic radiation
detector includes a light detector, an electron detector, or an ion
detector.
8. The apparatus of claim 2, wherein the computer is configured to
move the stage relative to the probe tip.
9. A method comprising: receiving a substrate having a sample
embedded therein; performing a first chemical characterization on a
probe tip using an electromagnetic radiation beam to generate a
first electromagnetic radiation signal for the probe tip; scanning
the substrate using the probe tip, wherein the probe tip secures to
the sample while scanning the substrate; performing a second
chemical characterization on the sample secured to the probe tip
using the electromagnetic radiation beam to generate a second
electromagnetic radiation signal; and generating a chemical
analysis for the sample by comparing the second electromagnetic
radiation signal with the first electromagnetic radiation
signal.
10. The method of claim 9, further comprising inspecting the
substrate using an inspection tool to locate the sample on the
substrate.
11. The method of claim 9, further comprising locating a source
generating the sample by using the chemical analysis for the
sample.
12. The method of claim 9, wherein using an electromagnetic
radiation beam includes using a light beam, an ion beam, or an
electron beam.
13. The method of claim 9, wherein the first electromagnetic
radiation signal is different from the second electromagnetic
radiation signal.
14. The method of claim 9, wherein comparing the second
electromagnetic radiation signal with the first electromagnetic
radiation signal includes using a difference between the first
electromagnetic radiation signal and the second electromagnetic
radiation signal.
15. The method of claim 9, wherein generating the chemical analysis
includes identifying a chemical component, or a chemical functional
group of the sample.
16. A method comprising: receiving a substrate having a defect;
performing a first chemical characterization on a probe tip using
an electromagnetic radiation beam to generate a first
electromagnetic radiation signal; scanning the substrate using the
probe tip installed on a holder integrated to a cantilever, wherein
the probe tip attaches to the defect from the substrate while
scanning; moving the defect attached on the probe tip away from
substrate after moving performing a second chemical
characterization on the probe tip and the attached defect using
another electromagnetic radiation beam to generate a second
electromagnetic radiation signal; and generating a chemical
analysis for the defect by comparing a difference between the first
electromagnetic radiation signal and the second electromagnetic
radiation signal.
17. The method of claim 16, further comprising locating a candidate
contamination source by using the chemical analysis.
18. The method of claim 16, wherein moving the defect attached on
the probe tip includes rotating the cantilever.
19. The method of claim 16, wherein moving the defect attached on
the probe tip includes removing the probe tip from the holder.
20. The method of claim 16, wherein generating the chemical
analysis for the defect includes identifying a chemical function
group of the defect.
Description
BACKGROUND
[0001] The semiconductor integrated circuit (IC) industry has
experienced exponential growth. Technological advances in IC
materials and design have produced generations of ICs where each
generation has smaller and more complex circuits than the previous
generation. In the course of IC evolution, functional density
(i.e., the number of interconnected devices per chip area) has
generally increased while geometry size (i.e., the smallest
component (or line) that can be created using a fabrication
process) has decreased. This scaling down process generally
provides benefits by increasing production efficiency and lowering
associated costs.
[0002] Defect analysis is an important aspect of the IC industry.
It is common for defects to occur in the substrate being
fabricated, such as a wafer with one or more dies, as well as in
masks used to fabricate the substrate. In light of the advanced
scaling that has occurred, smaller defects become more critical,
and more difficult to detect and analyze. Generally, tools such as
a transmission electron microscope (TEM) or an energy-dispersing
x-ray scanning electron microscope or energy dispersive X-ray
spectroscopy (collectively referred to as EDX) are used for defect
analysis. However, these tools often have difficulty with very
small defects, and for handling background signals. Also, sample
preparation for these tools are often very difficult to prepare,
and sometime require destroying the item (e.g., wafer or mask) to
be analyzed. Accordingly, what is needed is a method to analyze
defects in a quicker and more accurate way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The present disclosure is best understood from the following
detailed description when read with accompanying figures. It is
emphasized that, in accordance with the standard practice in the
industry, various features are not drawn to scale and are used for
illustration purpose only. In fact, the dimension of the various
features may be arbitrarily increased or reduced for clarity of
discussion.
[0004] FIG. 1 is a diagram of an analytical tool according to one
or more embodiments.
[0005] FIGS. 2A and 2B are diagrams of an apparatus for
charactering a defect on a substrate for benefitting from one or
more embodiments.
[0006] FIGS. 3A-D are examples of characterizing a defect on a
substrate for benefitting from one or more embodiments.
[0007] FIG. 4 is a flow char of characterizing a defect on a
substrate for benefitting from one or more embodiments.
DETAILED DESCRIPTION
[0008] The following disclosure provides many different
embodiments, or examples, for implementing different features of
the disclosure. Specific examples of components and arrangements
are described below to simplify the present disclosure. These are,
of course, merely examples and are not intended to be limiting. For
example, the formation of a first feature over or on a second
feature in the description that follows may include embodiments in
which the first and second features are formed in direct contact,
and may also include embodiments in which additional features may
be formed between the first and second features, such that the
first and second features may not be in direct contact. In
addition, the present disclosure may repeat reference numerals
and/or letters in the various examples. This repetition is for the
purpose of simplicity and clarity and does not in itself dictate a
relationship between the various embodiments and/or configurations
discussed.
[0009] Referring now to FIG. 1, a diagram of an analytical tool 100
for analyzing a defect falling on a substrate is illustrated
according to one or more embodiments. In the present embodiments, a
defect is also referred to as a foreign defect or a particle. The
analytical tool 100 includes an electromagnetic radiation source
102, an electromagnetic radiation beam 104, a stage 106, a signal
108, and a detector 110. It is understood that other configurations
and inclusion or omission of various items in the analytical tool
100 may be possible. In the depicted embodiment, the analytical
tool 100 is used to determine or characterize chemical component(s)
of a defect, such as a particle from an IC device, and find the
source of the defect in a semiconductor fab. A substrate may
include a wafer substrate, a mask substrate, a semiconductor
device, or a piece of material from a wafer substrate, a mask
substrate or a semiconductor device.
[0010] The electromagnetic radiation source 102 includes a source
generating the electromagnetic radiation beam 104, such as a light
beam, an electron beam, or an ion beam. The stage 106 is a place
securing a substrate and providing movement in X, Y and X direction
or rotation for a substrate. The stage 106 includes motors, roller
guides, and tables; secures a sample; provides the accurate
position and movement of a substrate in X, Y and Z directions; and
allow a electromagnetic radiation beam focusing on a defect falling
on a substrate. The signal 108 includes an electromagnetic
radiation pulse signal generated by an interaction between a defect
falling on a substrate and the electromagnetic radiation beam 104
focused on the defect. The detector 110 receives the signal 108
from a defect falling on a substrate and converts the signal 108 to
a chemical characterization, such as a spectrum of a chemical
function group or a chemical component profile of a defect falling
on a substrate using a computer. The detector 110 includes a light
detector, an electron detector, or an ion detector. The detector
110 also includes a processor to convert an electromagnetic
radiation pulse signal to a voltage signal used by a computer.
[0011] As shown in FIG. 1A, when the electromagnetic radiation beam
104 emitted from the electromagnetic radiation source 102 is
focused on a defect residing in/on a substrate secured on the stage
106, the signal 108 is detected by the detect 110. Depending on the
electromagnetic radiation source 102 and the detector 110, a
chemical characterization of the defect, such as a chemical
function spectrum or a chemical component profile of the defect is
determined using the electromagnetic radiation beam 104. For
example, a chemical function group of a defect is determined by
Fourier transfer infrared spectroscopy (FTIR). In another example,
a chemical component profile of a defect is determined by EDX. In
one embodiment, by knowing the chemical component profile of a
defect on a substrate using EDX, a contamination source generating
the defect can be identified and addressed.
[0012] Continuing with the present embodiment, while performing an
EDX technique on a defect on a substrate, a signal detected by a
detector not only includes a signal from the defect but also from
the substrate itself. In the present embodiments, a signal from a
substrate is referred as to a background signal or a noise.
Sometimes, a signal of a defect on a substrate is the same as the
background signal and therefor an EDX spectrum of the defect cannot
identify chemical components of the defect.
[0013] Referring to FIGS. 2A and 2B, diagrams of an apparatus 200
for analyzing a sample embedded in a substrate are illustrated for
implementing one or more embodiments. In the present embodiments, a
sample is also referred to as a defect. A sample includes an
inorganic compound, an organic compound, or combination thereof.
The apparatus 200 has a function of detaching a defect embedded in
a substrate from the substrate using a probe tip as shown in FIG.
2A and analyzing the sample attached on the probe tip using an
electromagnetic radiation beam as shown in FIG. 2B. The apparatus
200 includes a probe tip 202, a cantilever 204, a stage 206, an
electromagnetic radiation source 208, a detector 210, and a
computer 212. The cantilever 204 includes a holder 218 and a motor
220. It is understood that other configurations and inclusion or
omission of various items in the apparatus 200 may be possible. The
apparatus 200 is an example of embodiments, and is not intended to
limit the present invention beyond what is explicitly recited in
the claims.
[0014] The probe tip 202 is configured to install on the holder 218
integrated into the cantilever 204. The probe tip 202 includes a
metal, a metal compound, a carbon-based material, or another
material. The probe tip 202 has an adhesive property so that the
probe tip 202 can pick up a sample embedded in a substrate and
attaches the sample on the probe tip 202 while scanning surface of
a substrate, such as a wafer or a photomask. In some embodiments,
the probe tip 202 scans a designated area on a substrate in a
scanning rate, picks up and attaches a sample embedded in the
substrate to the probe tip 202, moves away from the surface of the
substrate with the sample attached on the probe tip 202, and allows
the electromagnetic radiation beam 214 focused on the sample
attached to the probe tip 202 for analysis. For example, the probe
tip 202 can attach a particle from a wafer when scanning a wafer,
move away from the wafer, and allow an electron beam to focus on
the particle to analyze chemical component of the particle.
Further, by knowing the chemical component of the particle, it is
possible to locate a source of the defect.
[0015] The cantilever 204 is configured to support the probe tip
202 and connect to the computer 206. The cantilever 204 integrates
the holder 218, holding one or more probe tips 202. The cantilever
204 also integrates the motor 220, moving and rotating the probe
tip 202 away from a surface of a substrate. The cantilever 204 may
include a metal or a metal alloy. The cantilever 204 is designed to
the support probe tip 202, move in X, Y or Z direction, or rotate
with the probe tip 202 during and after scanning. For example, the
cantilever 204 supports the probe tip 202 while the probe tip 202
is scanning a substrate, and then moves or rotates the probe tip
202 in the designated angle with a sample attached to the probe tip
202 after scanning, so that the electromagnetic radiation beam 214
can focus on the sample and a chemical analysis can be performed on
the sample without interference from the substrate.
[0016] The stage 206 is for securing a substrate and providing
relative movement of the substrate when the probe tip 202 is
scanning. The stage 206 connects to the computer 212. The stage 206
includes motors, roller guides, and tables; secures a substrate by
vacuum; and provides the accurate position and movement of the
substrate in X, Y and Z directions during the probe tip 202
scanning. In one embodiment, scanning a substrate includes moving
the stage 206 while the probe tip 202 is in a static position. In
another embodiment, scanning a substrate includes moving the probe
tip 202 by moving the cantilever 204 while the stage 206 is in a
static position.
[0017] The electromagnetic radiation source 208 is configured to
provide the electromagnetic radiation beam 214 for performing a
chemical analysis or a chemical characterization on a sample picked
from a substrate by the probe tip 202. The electromagnetic
radiation source 208 connects to the computer 212. The
electromagnetic radiation source 208 includes a source generating
the electromagnetic radiation beam 214, such as a light beam, an
electron beam, or an ion beam. In the present embodiments, various
electromagnetic radiation beams are used for chemical analysis. For
examples, an electron beam is used to determine chemical component
of the sample in the apparatus 200, such as in an EDX or in an
Auger electron spectroscopy (AES); a light beam is used to
determine a chemical functional group of the sample in the
apparatus 200, such as in an FTIR; and an ion beam is used to
determine chemical components of the sample in the apparatus 200,
such as in a secondary ion mass spectroscopy (SIMS).
[0018] The electromagnetic radiation detector 210 is configured to
detect the electromagnetic radiation signal 216 emitted from a
sample attached on the probe tip 202 when the electromagnetic
radiation beam 214 is projected or focused on the sample. In the
present embodiments, an electromagnetic radiation signal is also
referred to as a signal. The electromagnetic radiation detector 208
connects to the computer 210. The electromagnetic radiation
detector 208 includes a converter converting an electromagnetic
radiation signal to a voltage signal for the computer 212
processing. The electromagnetic radiation detector 210 includes a
light detector, an electron detector, or an ion detector. In the
present embodiments, various detectors are used for chemical
characterization of a sample attached on the probe tip 202. For
example, an electron detector is used to determine chemical
components of the defect in the apparatus 200, such as in an EDX or
an AES, a light detector is used to determine a chemical functional
group of the sample in the apparatus 200, such as in a FTIR; and an
ion detector is used determine chemical component of the defect in
the apparatus 200, such as in a SIMS.
[0019] The computer 212 is a standard, general-purpose computer,
including a processor, a database (memory), and interface. The
computer 212 may be a single computer or a distributed computer,
and connects to various components such as the cantilever 204, the
stage 206, the electromagnetic radiation source 208, and the
electromagnetic radiation detector 210 as shown in FIGS. 2A and 2B.
The computer 212 includes one or more software programs for
controlling one or more components of the apparatus 200 during and
after scanning, picking a sample from the substrate, analyzing the
sample, and summarizing a chemical characterization of the
sample.
[0020] The computer 212 controls the stage movement in X, Y and Z
direction during the probe tip 212 scanning to pick up a sample in
an interested area. The computer 212 also controls the cantilever
204 to move or rotate so that the sample attached at the probe tip
212 is moved away from the substrate. The computer 212 also
controls an electromagnetic radiation beam emitted from the
electromagnetic radiation source 208 to focus on the sample for a
chemical characterization of the defect. The computer 212 further
controls the detector 210 to receive a signal and convert the
signal to a signal for processing. The computer 212 also provides a
report of the chemical characterization of the sample.
[0021] The electromagnetic radiation beam 214 is generated by the
electromagnetic radiation source 208 and is focused on a defect
attached on the probe tip 202. The electromagnetic radiation beam
214 includes a light beam, an electron beam or an ion beam. The
electromagnetic radiation signal 216 is generated by an interaction
between the electromagnetic radiation beam 214 and the sample
attached on the probe tip 202. The electromagnetic radiation signal
216 includes a light radiation pulse, an electron radiation pulse,
or an ion radiation pulse. The electromagnetic radiation signal 216
may reveal chemical characterizations of the sample attached on the
probe tip 202, such as chemical structure, chemical function group,
or chemical component of the sample.
[0022] For example, while a light beam is focus on a sample (a
defect), the light beam interacts with a chemical bond of the
sample and a signal generated by the interaction uncovers a
chemical function group of the sample. This principle is used in
optical spectroscopy, such as FTIR. In another example, while an
electron beam is focused on a sample (e.g. a defect), the electron
beam interacts with orbit electrons of a chemical element of the
sample and a signal generated by the interaction reveals chemical
component of the sample. This principle is used in an electron
spectroscopy, such as an EDX or AES. In an alternative example,
while an electron beam is focused on a sample (e.g. a defect), the
ion beam interacts with orbit electrons of a chemical element of
the sample and a signal generated by the interaction uncovers
chemical component of the sample. This principle is used in another
electron spectroscopy, such as SIMS.
[0023] According to one or more embodiments, the apparatus 200 can
perform a chemical characterization on a sample, such as a defect
attached on the probe tip 202, with minimum or without interference
from the environment surrounding the sample. For example, a
substrate, such as a wafer, with a defect embedded on the substrate
is provided to the apparatus 200 for chemical characterization of
the defect to locate a possible source of the defect. The probe tip
202 scans an interested area on the substrate loaded on the stage
206 and attaches the defect on the probe tip 202; the defect moves
away from the substrate by moving or rotating the probe tip 202
attached on the cantilever 204; the electromagnetic radiation
source 208, such as an electron source, generates the
electromagnetic radiation beam 214, such as an electron beam, to
focus on the defect; the electromagnetic radiation detector 210
receive a signal, such as an escaped electron, generated between an
interaction between the electron beam and orbit electron of a
chemical element in the defect, and converts the signal to a
voltage signal; and the computer 212 receives the voltage signal
and generates a report of chemical component of the defect. In some
embodiments, because the probe tip 202 is significantly different
from a defect attached on the tip and an interference of the probe
tip 202 is minimized, performing a chemical characterization on a
defect is more accurate and quick.
[0024] Referring to the examples of FIGS. 3A-D, a defect 302 is
embedded on a wafer or mask 304, the foreign defect 302 is attached
on the probe tip 202 using the apparatus 200 as shown in FIGS. 2A
and 2B, a chemical component profile 306 is generated using the
electromagnetic radiation source 208 and the electromagnetic
radiation detector 210, and the defect 302 includes elements Fe and
S calculated by the computer 212 by comparing the chemical
component profile 306 with a chemical component profile 308 of the
probe tip 202. Further, a possible contamination or defect source
is located by knowing the chemical component of the defect. That
is, certain tools or processing steps are known to be associated
with the defect 302, and once the chemical properties of the defect
are identified and analyzed, the corresponding tool or processing
step can be identified.
[0025] Referring to FIG. 4, a flow chart of a method 400 for
characterizing a sample embedded on a substrate using the apparatus
200 is illustrated for benefiting from one or more embodiments. The
method 400 begins at step 402 by providing a substrate having a
sample embedded therein. In the present embodiments, the substrate
is a wafer, such as a silicon wafer. Alternatively or additionally,
the substrate includes another elementary semiconductor, such as
germanium; a compound semiconductor including silicon carbide,
gallium arsenic, gallium phosphide, indium phosphide, indium
arsenide, and/or indium antimonide; or an alloy semiconductor
including SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, and/or
GaInAsP. In yet another alternative, the substrate includes a
semiconductor on insulator (SOI) structure. The substrate further
includes various doped features, such as n-type wells and/or p-type
wells, formed by ion implantation or diffusion. The substrate also
includes various isolation features, such as shallow trench
isolation (STI), formed by a process, such as a process including
etching to form various trenches and then depositing to fill the
trench with a dielectric material.
[0026] In the present embodiments, the substrate also includes one
or more conductive and/or dielectric films. In the present
embodiment, the dielectric film may include silicon oxide, high k
dielectric material film, or a combination of silicon oxide and
high k dielectric material, and the conductive thin film for the
gate electrode film may include doped polysilicon, or a metal, such
as aluminum (Al), copper (Cu), tungsten (W), nickel (Ni), titanium
(Ti), gold (Au), platinum (Pt) or alloy of the metals thereof.
[0027] In the present embodiments, a sample, such as a defect, has
previously formed on the substrate during some part of the wafer
fabrication. For example, the defect is formed while depositing a
conducting or a non-conductive film on the wafer. In another
example, the defect is formed while baking the wafer in an oven or
on a hot plate chamber. In another example, the defect is formed
while measuring the wafer with a measurement tool.
[0028] The method 400 proceeds to step 404 to locate the sample
embedded in the substrate. In the present example, an interested
area on the wafer is identified, such as a die area or a wafer
edge. The probe tip is moved to the interested area to scan and
pick up a sample. Step 404 includes inspecting the substrate using
an inspection tool, such as a wafer inspection tool or a photomask
inspection tool. Step 404 also includes sending coordinates of the
sample to a computer. The probe tip can then be positioned for the
next step.
[0029] The method 400 proceeds to step 406 by performing a chemical
characterization on the probe tip using an electromagnetic
radiation beam. Step 406 provides a first electromagnetic radiation
signal generated from an interaction between the electromagnetic
radiation beam and the probe tip. Step 406 includes focusing an
electromagnetic radiation beam on the probe tip and collecting an
electromagnetic radiation signal generated from an interaction
between a probe tip and an electromagnetic radiation beam focused
on the probe tip using a detector. The first electromagnetic
radiation signal is then stored in a database of a computer system,
as a baseline for the probe tip. Step 410 also includes generating
a chemical analysis for the probe tip using the first
electromagnetic radiation signal by the computer. In the present
embodiments, this step is also referred to as a calibration of a
probe tip using an electromagnetic radiation beam.
[0030] The method 400 proceeds to step 408 by attaching the sample
embedded in/on the substrate onto the probe tip. Step 408 includes
scanning the interested area and picking up the sample by the probe
tip during or after scanning. In some embodiments, scanning an
interested area on the substrate includes running the probe tip
near a top surface of the substrate. In other embodiments, scanning
an interested area on a substrate includes using the probe tip in a
morphology tool, such as a probe tip in an atomic force microscope
(AFM). The probe tip with sample can then be positioned for the
next step.
[0031] The method 400 proceeds to step 410 by performing a chemical
characterization on the sample attached on a probe tip. This
includes focusing an electromagnetic radiation beam on the sample
and collecting a second electromagnetic radiation signal generated
therefrom. Step 410 further includes converting the electromagnetic
signal to a voltage signal for a computer to process.
[0032] The method 400 proceeds to step 412 by calculating a
chemical analysis for the sample. Step 412 includes comparing the
second electromagnetic radiation signal with the first
electromagnetic radiation signal. Step 412 may include subtracting
the first electromagnetic radiation signal from the second
electromagnetic radiation signal. In the present embodiments, a
chemical analysis includes a chemical function group, a chemical
component profile, or a chemical component report.
[0033] In some embodiments, performing a chemical characterization
of the sample includes unloading the probe tip with the sample
attached to the probe tip, loading the sample attached on the probe
tip to an analytical tool, and performing the chemical
characterization on the sample. In one example, a chemical function
group is determined by loading the probe tip with the sample to a
FTIR and using a light beam of the FTIR focusing on the sample
attached on the probe tip. In another example, a chemical component
profile is generated by loading the probe tip with the sample to an
EDX and using an electron beam of the EDX focusing on the
sample.
[0034] In other embodiments, performing a chemical characterization
of a sample includes using the apparatus 200 as shown in FIGS. 2A
and 2B by rotating the cantilever 204 such that the sample attached
to the probe tip 202 moves away from the substrate and an
electromagnetic radiation beam focuses on the sample for a chemical
characterization. In one example, the electromagnetic radiation
beam includes a light beam and a chemical function group of the
sample is determined by the light beam interaction with the sample.
In another example, the electromagnetic radiation beam includes an
electron beam and a chemical component profile of the sample is
determined by the electron beam interaction with the sample.
[0035] The method 400 proceeds to step 414 by locating a source of
the defect. This includes tracing a possible source of the defect
based on the chemical analysis, such as a chemical component
profile or a chemical function group of the defect. Examples
include a resist splash on a wafer, a chemical buildup on a
deposition chamber or a heating chamber, a haze growth on a
photomask, and a chemical scratch on a wafer. Step 414 also
includes performing a maintenance procedure to clean, replace or
fix the source of the defect.
[0036] In the present embodiments, it is understood that additional
steps can be provided before, during, and after the method 400, and
some the steps described can be replaced, eliminated, or moved
around for additional embodiments of the method 400. The method 400
is example embodiments, and is not intended to limit the present
invention beyond what is explicitly recited in the claims.
[0037] Thus, the present disclosure describes an apparatus for
analyzing a sample embedded in a substrate. The apparatus includes
a probe tip configured to scan a substrate having a sample to
attach the sample on the probe tip while scanning the substrate,
wherein a first electromagnetic radiation signal is generated while
an electromagnetic radiation beam focusing on the probe tip and a
second electromagnetic radiation signal is generated when the
electromagnetic radiation beam focusing on the sample attached on
the probe tip, a cantilever configured to integrate a holder
holding at least one probe tip, wherein the cantilever moves the
sample attached on the probe tip away from the substrate so that
the electromagnetic radiation beam can focus on the sample attached
on the probe tip, a stage configured to secure the substrate, an
electromagnetic radiation source configured to generate the
electromagnetic radiation beam, and an electromagnetic radiation
detector configured to receive the first electromagnetic radiation
signal and the second electromagnetic radiation signal. The
apparatus also includes a computer configured to connect the
cantilever, the stage, the electromagnetic radiation source, and
the electromagnetic radiation detector.
[0038] In one or more embodiments, a method of analyzing a sample
embedded in a substrate is described. The method includes receiving
a substrate having a sample embedded in the substrate, performing a
first chemical characterization on a probe tip using an
electromagnetic radiation beam to generate a first electromagnetic
radiation signal by the probe tip, scanning the substrate using the
probe tip, wherein the probe tip picks the sample from the
substrate while scanning the substrate, performing a second
chemical characterization on the sample attached on the probe tip
using the electromagnetic radiation beam to generate a second
electromagnetic radiation signal by the sample and the probe tip,
and generating a chemical analysis for the sample by comparing the
second electromagnetic radiation signal with the first
electromagnetic radiation signal. The method also includes
inspecting the substrate using an inspection tool to locate the
sample on the substrate. The method further includes locating a
source generating the sample by using the chemical analysis for the
sample.
[0039] In some embodiments, a method of analyzing a defect embedded
in a substrate is presented. The method includes receiving a
substrate having a defect embedded in the substrate, performing a
first chemical characterization on a probe tip using an
electromagnetic radiation beam to generate a first electromagnetic
radiation signal by the probe tip, scanning the substrate using the
probe tip installed on a holder integrated to a cantilever, wherein
the probe tip picks the defect from the substrate while scanning
the substrate, moving the defect attached on the probe tip away
from substrate so that the electromagnetic radiation beam focuses
on the defect attached on the probe tip to generate a second
electromagnetic radiation signal by the defect and the probe tip
without interference from the substrate, and generating a chemical
analysis for the defect by using a difference between the first
electromagnetic radiation signal and the second electromagnetic
radiation signal. The method further includes locating a
contamination source generating the defect by using the chemical
analysis for the defect so that the contamination source is
fixed.
[0040] The foregoing outlines features of several embodiments so
that those skilled in the art may better understand the aspects of
the present disclosure. Those skilled in the art should appreciate
that they may readily use the present disclosure as a basis for
designing or modifying other processes and structures for carrying
out the same purposes and/or achieving the same advantages of the
embodiments introduced herein. Those skilled in the art should also
realize that such equivalent constructions do not depart from the
spirit and scope of the present disclosure, and that they may make
various changes, substitutions, and alterations herein without
departing from the spirit and scope of the present disclosure.
* * * * *