Abhijeet “AJ” Joshi, PhD. 2015 Pg. 1 - NCCAVS …...2015 Pg. 4 FAaST (CV), 4-Point Probe, Bulk...
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Pg. 1 2015 Abhijeet “AJ” Joshi, PhD.
Transcript of Abhijeet “AJ” Joshi, PhD. 2015 Pg. 1 - NCCAVS …...2015 Pg. 4 FAaST (CV), 4-Point Probe, Bulk...
Pg. 1 2015
Abhijeet “AJ” Joshi, PhD.
Pg. 2 2015
Current Techniques
Non-Electrical Data & Electrical Data
Resistance based: Scanning Spreading Resistance Microscopy (SSRM)
Charge based: Electro-Chemical CV (E-CV)
Is the Data Complete?
Analytical Process
Germanium Data
Outline
Pg. 3 2015
1. Microscopy: Optical, SEM, FIB-SEM
2. Transmission Electron Microscopy
3. Scanning Probe Techniques: SPM, SSRM
4. Secondary Ion Mass Spectroscopy (SIMS)
5. Electro-Chemical CV
6. X-Ray Photoelectron Spec. /Auger ES
7. Atom Probe Tomography (APT)
8. Low energy Electron induced X-ray Emission Spectrometry
(LEXES)
9. X-Ray Diffraction Techniques
Techniques Currently Used
Pg. 4 2015
FAaST (CV), 4-Point Probe, Bulk Hall – Single Point
Scanning Spreading Resistance Microscopy (SSRM)
Electro-Chemical CV (E-CV)
….and that’s it!
Electrical Techniques
PROCESS CHANGES CHANGES IN ELECTRICAL
BEHAVIOR ?
Pg. 5 2015
Provides Spreading Resistance ONLY
AFM based technique – 2D imaging
SSRM
[1]J Mody et al. IEDM 2011
[2] Eyben et al. Mat. Sci. Engr B 124-125 (2005)
Applications: Local Assessment of partial electrical image
Pg. 6 2015
E-CV Technique
E-CV relies on measurement of both Cs and Celectrolyte
Nanometrics’ E-CV Pro uses a 3-term model
Cs is very small and thus dominates
[1] From Nanometrics E-CV Pro Literature
Pg. 7 2015
Resistance Profiles (Ω or ρ) : SSRM
Charge/ Activation Profiles (n) : E-CV
Is the Dataset Complete?
𝑛(𝑥) =1
µ 𝑥 ρ 𝑥 𝑞 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛
Carriers
(n)
Mobility
(µ)
Resistivity
(ρ)
Pg. 8 2015
Majority Carrier Mobility (µ)
Sheet Resistance (Rs ) and Resistivity (ρ)
Active Carrier Concentration (n)
COMPLETE Electrical Profiles
PROCESS CHANGES CHANGES IN ELECTRICAL
SIGNATURES ALPInc.’s
DHE
Pg. 9 2015
DHE System: Analytical Process
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• Blends the Best of E-CV and Hall Measurements:
• Low Sample Prep. Burden
• Measurement of Resistivity AND Mobility
• Customizable Step-size
• User determined step-resolution [from 3-5 Angstroms and up]
𝑛(𝑥) =1
µ 𝑥 ρ 𝑥 𝑞 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛
Direct measurements
Pg. 10 2015
ALP Differential Hall Effect (DHE) System
• Measurement Resolution ~3-5 Angstroms
• Room Temperature Process – No Thermal Steps required
• Clean Procedure
• Fully Automated Measurement Operation – Repeatability
• Provides Junction profiles for n, µ and ρ
Pg. 11 2015
Germanium Data
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• Courtesy: John Borland
• Epi-Germanium – Laser Anneal Split
• Ph doped in Ge in-situ
• ACTUAL Electrical Junction Location
Pg. 12 2015
Bulk Properties
Property Ph:Ge 0.5J/cm2 Ph:Ge 1J/cm2 Ph:Ge 2J/cm2
Average Bulk Drift Mobility (cm2/V-s)
196.94 148.06 42.16
Average Dose (#/cm2)
6.05E+14 1.75E+15 8.72E+15
Bulk Sheet Resistance (Ohm/Sq.)
52.44 24.16 16.99
Pg. 13 2015
Bulk Sheet Resistance
0
20
40
60
80
100
120
140
0 1000 2000 3000 4000
Ohm
/sq.
Depth (A)
Bulk Sheet Resistance
Ph:Ge 0.5J/cm2
Ph:Ge 1J/cm2
Ph:Ge 2J/cm2
Pg. 14 2015
Layer Resistivity
0
0.005
0.01
0.015
0.02
0 1000 2000 3000 4000
Ohm
-cm
Depth (A)
Layer Resistivity
Ph: Ge 0.5J/cm2
Ph:Ge 1J/cm2
Ph:Ge 2J/cm2
Pg. 15 2015
Layer Mobility Data
0
100
200
300
400
500
600
700
800
0 1000 2000 3000 4000
Mobilit
y(
cm
2/V
-s)
Depth (A)
Layer Mobility
Ph:Ge 2J/cm2
0
100
200
300
400
500
600
700
800
0 1000 2000 3000 4000
Mobilit
y(
cm
2/V
-s)
Depth (A)
Layer Mobility
Ph:Ge 1 J/cm2
0
100
200
300
400
500
600
700
800
0 1000 2000 3000 4000
Ph:Ge 0.5J/cm2
Pg. 16 2015
Conclusions: Germanium Data
• Material Study
• Measured Electrical Activation variation with Fluence
Pg. 17 2015
Carriers Vs Resistivity
1.00E+17
1.00E+18
1.00E+19
1.00E+20
1.00E+21
0 0.002 0.004 0.006
#/c
m3
Resistivity (Ohm-cm)
High Activation +
Low Resistivity
High Activation +
High Resistivity
Mobility Enhancement +
High Resistivity
Mobility
Enhancement +
Low Resistivity
Ideal Curve
Pg. 18 2015
Carriers Vs Resistivity
• 1J/cm2 ~ 200nm Junction
1E+18
1E+19
1E+20
1E+21
0 0.001 0.002 0.003 0.004 0.005
Carr
ier
Conc.
(#/c
m3)
Depth (A)
Carrier Concentration
Ph:Ge 0.5J/cm2
Ph:Ge 1J/cm2
Ph:Ge 2J/cm2
Cutriss Model
Pg. 19 2015
More Germanium
• Sb Vs Sb + Sn
• Laser Anneal
• Concentration Vs Resistivity Parametric Curves
Pg. 20 2015
Carriers Vs Resistivity - 1.1J/cm2
• Adding Sn to Sb gets us CLOSER to the IDEAL curve
1.E+18
1.E+19
1.E+20
1.E+21
1.E+22
0 0.0005 0.001 0.0015 0.002
#/c
m3
Resistivity (ohm-cm)
Cuttriss Model
Cuttriss Model Extended
Sb 1.1, Measured
Sb Sn 1.1, Measured
