SEMILAB’s PRODUCTS
for the
SEMICONDUCTOR INDUSTRY
SEMILAB Semiconductor Physics Laboratory, Inc.
Prielle Kornelia u. 2, H-1117 Budapest, Hungary
Tel:36-1-382-4530
Fax: 36-1-382-4532
E-mail: semilab@semilab.hu
Web site: www.semilab.com
www.semilab.com
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Semiconductor Characterization Systems
Wafer Mapping Tools
Bulk Microdefect Analyzer
Deep Level Spectrometer
for high speed, high resolution whole
wafer mapping of defects and/or
contaminants
for imaging of extended defects (from
20nm to several micron)
for identification of electrically active point
defects
Resistivity Tester
p/n Tester
for non-contact determination of bulk
resistivity
for non-contact determination of
conductivity type (p or n) of the material
in blocks and feedstock material
in wafers
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Wafer Mapping Tools
WT-2000 Wafer Tester
monitoring defects and contamination both in the bulk and in the surface region
of silicon wafers
Applied measurement techniques:
m-PCD
for bulk Si
Charge-PCD
for bare wafers
EpiTest
for epi wafers
SPV
for bulk Si
V-Q
for oxide characterization
Eddy current for resistivity mapping
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In-line Monitoring Tool
WT-3000 model for
in-line
contamination monitoring
•
SPC product wafer
•
Iron contamination mapping - 10x faster than SPV
•
Full wafer monitoring due to high mapping speed
•
Integrated minienvironment including FOUP
loadport, robot and pre-aligner
Fe
Fe
Fe
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WT-2000 m-PCD Tool
m-PCD (microwave photoconductive decay) technique for mapping crystal growth and
process induced defects and heavy metal contamination in bulk silicon wafers
APPLICATIONS
CRYSTAL GROWTH DEFECTS
Laser
Microwave
wafer
I = I0 e-t/t
Slip lines
Oxygen striations
OSF ring
PROCESS INDUCED DEFECTS/Fe MAPPING
Fe
Fe
Fe
Contaminated
vacuum chuck
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Boat contamination
Fe detection
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WT-2000 SPV Tool
Surface Photovoltage (SPV) technique for mapping heavy metal contamination and crystal
defects in the bulk silicon wafer
IRON CONCENTRATION
MAPPING
F/VSPV
4
1
3
NFe = C (
1
1
Lafter2
-
1
Lbefore2
)
Lifetime, ms
2
L
Fe AND O2 MONITORING BY
COMBINED m-PCD AND SPV
TECHNIQUES
Fe-B pair
O2 prec.
0.1
0.01
1.E+11
1/a
m-PCD
SPV
1.E+13
1.E+15
1.E+17
Injection level, 1/cm3
F
= C(L+1/a)
VSPV
oxygen
SPV
iron
m-PCD
Fe
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WT-2000 Charge-PCD
Semilab’s patented new surface passivation method applying controlled charge
deposition on to the wafer surface during lifetime mapping provides a highly efficient,
reproducible and homogeneous surface recombination elimination on bare wafers.
Lifetime map measured
with charging
without charging
Laser
Microwave
Charging
wafer
Charging
1
tmeas
1
1
1
+ t +t
=t
bulk
diff
surf
taverage=15.7 ms
taverage=268 ms
Surface /interface characterization
Interface recombination velocity
map of an oxidized wafer
calculated from the lifetime map
measured with and without
charging on the same wafer
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WT-2000 V-Q Tool
Fast, non-contact measurement technique, that replace the traditional contact C-V
measurements for qualifying the oxide/interface in silicon wafer
Electrical oxide thickness
Non-contact V-Q combines
three non-contact methods:
Charge Light/Kelvin probe
...........
SPV, V
Theoritical
0.5
Darkcorrected bright
-0.5
100
• Corona discharge
• Kelvin Probe
• Illumination
o
1
0
o
26 A
0
Charge, nC/cm2
100
Tox
Vfb
Dit
Qm
Vox
Qeff
Etunnel
Vs
Vsurf
Vtunnel
Electrical oxide thickness
Flatband voltage
Interface state density
Mobile charge
Oxide voltage
Effective charge
Tunelleing electric field
Surface potential
Surface voltage
Tunnel voltage
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24 A
Etunnel
-11V
-6.8V
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WT-2000 Epitest
Improved m-PCD (microwave photoconductive decay) technique for the characterization
of recombination processes in epi structures.
Lifetime map
Light excitation
Green laser
532nm
Oxide or passivation
Ssurface
Epi layer
Sinterface
Fe concentration map
Microwave
tep
i
tsubstrate
p+ or n+ substrate
13.8ms
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14.8ms
5 E9
1/cm3
3 E10
1/cm3
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WT-2000 Resistivity Mapper
Non-contact whole wafer resistivity mapping based on the eddy current technique for the
determination of bulk resistivity distribution in silicon wafers
Resistivity map
Head
height
control
Control
electronics
Single crystal
8” CZ wafer
Multi-crystalline
PV material
High frequency coil
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WT-2000 MCT
Temperature Dependent Lifetime
Monitoring minority carrier lifetime as a function of temperature in narrow band gap
semiconductors (InSb, HgCdTe, etc.)
Two measurement strategies:
• whole wafer mapping at a preselected stabilized temperature
between 85K and 300K
• single point lifetime plot as a function of temperature
between 85K and 300K
Temperature dependent carrier lifetime measurements
0.16
HgCdTe
InSb
0.14
0.5
sa m p le 1
sample#2
sample#4
sa m p le 2
0.4
0.12
0.3
0.10
0 .1
Lifetime [µs]
Lifetime [µs]
L ife tim e [µ s]
1
0.2
0.08
0.06
0.1
0.04
0 .0 1
50
100
150
T e m p e ra tu re [K ]
200
250
50
100
150
200
250
Temperature [K]
0.02
100
150
200
250
Temperature [K]
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300
SIRM-300
Bulk Microdefect Analyzer
Non-contact, non-destructive method based on reflection mode confocal microscopy
for detection and analysis of bulk microdefects
Dislocations
Stacking fault
laser
beamsplitter
detector
Denuded zone determination
Z scanning
wafer
X-Y scanning
depth
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Light Scattering Tomograph
Micro- and Grown-in Defects Analyzer
The BMDs scatter the incident light which is recorded by a CCD camera near to the cleaved edge of the sample
•High Sensitivity - Detectable Particle Size down to 10 nm
•High Depth Resolution - 0.5 μm
•High Measurement Speed, 50 sec/2mm x 400 μm
•Fully automatic operation including half wafer handling
•Stabilized Laser Wavelength
•Variable Laser Power
Near surface analysis
surface
5mm
Cumulative BMD number
0
50
100
150
200
Depth [µm]
0
10
DNZ depth: 18.9µm
y=0.2508x+18.896
20
R2 = 0.9969
30
40
Denuded zone determination
50
60
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DLS-83D
Deep Level Spectrometer
Detection and identification of trace level of impurities in concentrations down to 109 atoms/cm3
Radiation defects
in n-type FZ silicon
in p-type FZ silicon
Cs-Sii-Cs
Ps-Ci(1)
Vac-Vac
Ps-Ci(2)
P-Vac
Vac-Vac
Vac-O
CRYOSTATS
IN DIFFERENT TEMPERATURE RANGES
• Closed Cycle He-cryostat from 20K to 300K
• LN2 cryostats from 77K to 450K:
simple bath type LN2 cryostat
automatic LN2 cryostat with controlled LN2 flow
?
Ci
Cs-Oi
or
C-O-V2
Vac-?
Influence of annealing
on Fe-B pairs
Molybdenum
SAMPLE HOLDER
Fe-interstitial
Fe-B pair
with motor driven positioning
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Epimet
Fast, Repeatable Measurements Without Wafer Damage
Epimet delivers the industry’s first realtime, non-contact
method to measure epi layer resistivity profiles in
production. Fast feedback and the availability of resistivity
profile plots and wafer maps aid in troubleshooting for still
higher control over epi processes.
Resitivity profile measured by Epimet
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Surface Charge Analyzer
SiO2
+
-
Wd
p-type
silicon
Depletion width, Wd(mm)
The Surface Charge Analyzer allows real-time monitoring of contamination and damage in the critical
semiconductor manufacturing processes, such as thermal oxidation, CVD film deposition, metallization, and etch
processes.
Photons (Light)
Typical SCA Curve
Onset on Inversion
Inversion
Midgap
P-type Oxidized Wafer
Nsc
Qox
Dit
Accumulation
Induced charge, Qind
Wafer maps indicating backstreaming
Source
Avg Qox: 8E10q/cm2
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Load
Avg Qox: 2E11q/cm2
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