Digital Integrated Circuits © Prentice Hall 1995 Manufacturing Process CMOS Manufacturing Process.
Advantages of Ion Cluster Implantation In CMOS Manufacturing€¦ · In CMOS Manufacturing...
Transcript of Advantages of Ion Cluster Implantation In CMOS Manufacturing€¦ · In CMOS Manufacturing...
© 2006 SemEquip, Inc. Confidential and Proprietary
Advantages of Ion Cluster Implantation
In CMOS Manufacturing
Advantages of Ion Cluster Implantation
In CMOS Manufacturing
Thomas Horsky
Junction Technology Group
Semicon West, July 19 2007
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 2
Outline
Cluster concept
Types of ion clusters
Productivity enhancement
Activation
Junction leakage
Defects
Amorphization; crystal regrowth
Carbon for diffusion control
Stress engineering with SiC for NMOS channel mobility enhancement
Channeling & implant energy control
Summary
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 3
Cluster Concept—Productivity Advantage
18 dopant atoms per cluster
Increases effective dose rate by 18X
Extract and transport at 20X higher energy
Reduces net current to wafer by 18X (reduced
charging)
Deceleration is not required, eliminating energy
contamination
Enables cost-effective low energy, high dose
Implants
Low angular divergence low-energy beams at wafer
+ 20 keV B18Hx+
1 mA
+
18 mA
1 keV B+
Is process equivalent to
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 4
Process Advantages of B18H22 ImplantationAdvanced Logic & Memory
Higher ThroughputProduction-worthy throughput for doses up to 3E16cm-2; enabling for dual gate poly doping, contact plug, deep S/D
Up to 50mA B even at low (1-4 keV)
>100WPH at 200eV PMOS SDE (32nm design rule)
No Energy ContaminationAll implants are in drift mode
Enables abrupt junctions
Reduced risk of Vth shifts due to gate punch-through
Simplified Process FlowNo Ge or Si pre-amorphization needed due to self-amorphization property of cluster
Shallower as-implanted profiles→ conventional spike anneals can be used for USJ
Improved Device CharacteristicsNo implanted F, which can promote through-gate dopant diffusion
Conventional beam line means tight dose & energy control
Low angular divergence at wafer leads to abrupt junctions, reduces Vth variation due to shadowing
Improved dopant activation at low thermal budget due to self-amorphization
Lower leakage because there are no end-of-range defects (perfect re-crystallization is possible)
Much reduced angular divergence and improved spatial uniformity for MC and serial HC compared to low-energy monomer beams
Enables high tilt, under-the-gate implants (e.g., Halo)
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 5
Cluster Species Available with ClusterIon® Source
B18H22, B10H14
C16H10, C7H7
As4, P4
Arsenic Spectrum
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 50 100 150 200 250 300 350
Mass (AMU)
As+ C
urre
nt (m
A)
As4+
As2+
0200400600800
100012001400
0 25 50 75 100 125 150 175 200 225 250Mass (AMU)
Fara
day
Cur
rent
(uA
)B18H22 Spectrum
B18Hx+
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 6
L. Rubin et al., IWJT2007 (Axcelis)HC Drift Mode Performance of Optima Implanter
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 7
What implants can be better done with Clusters?
B18H22 , P4 and As4 can be used for USJ n+ and p+:
Source/Drain Extension
Deep Source/Drain
Poly Gate
Halo
Source Drain
Poly Gate
Ext + Pre–amorphizing
Well
Ext
Halo
Vt ADJ
Punch Through
Planar CMOS Structure
SDE: 100 eV—2 keV, 1E14—1E15
S/D: 1 keV—8 keV, 1E15—7E15
Halo: 3 keV—10 keV, 1E13—1E14
Poly: 1.5 keV—4 keV, 7E15—3E16
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 8
Scaling Challenges
Precision dopant placement is critical for source drain extension implants (angle control)
HALO implants requiring higher dose, lower energy to improve electrical performance in the channel
Repeatable implant profiles require ZERO energy contamination
Advanced Logic 65nm & 45nm DRAM Development 90nm & 70nm
Poly implants requiring lower energies and higher doses; < 5keV, ≥ 1.0E16
Zero tolerance for energy contamination in gate oxide
Slide Courtesy of Axcelis Technologies
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 9
L. Rubin et al., IWJT2007 (Axcelis)
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 10
Comparison of PLAD & Beamline DopingJ. Borland et al, IWJT2007
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 11
Akira Mineji et al., IWJT2007 (NEC, NIC, JOB)750 eV, 1E15 B SDE
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 12
Borland et al., IWJT2007
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 13
Summary of RsL and PLi Metrology ResultsJohn Borland et al., IWJT2007 (Selete, Nanometrics)
(SPE at 650C)
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 14
Junction Leakage Current
Non-PAI B18 has > 2 orders of magnitude lower junction leakage current using diffusion-less laser and SPE anneals
This is consistent with low damage junction in PL results
1.00E-08
1.00E-07
1.00E-06
1.00E-05
1.00E-04
1.00E-03
1.00E-02
1.00E-01
1.00E+00
B B+PAI BF2 BF2 + PAI B18 B18 + PAI
RsL
Lea
kage
Cur
rent
(A/c
m2)
Spike 1000Spike 1080Flash 1300Laser 1300SPE 650
After John Borland et al., IWJT2006, May 15—16, 2006, Shanghai, China, pp. 4—9.
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 15
Silicon Crystal Lattice Damage(JOB & NEC, IWJT2006 & SST2006)
0
10
20
30
40
50
60
70
80
90
100
B B+PAI BF2 BF2 + PAI B18 B18 + PAI
PL (a
rbitr
ary
units
)as -im plant(c ontrol)S pike 1000S pike 1080Flas h 1300Las er 1300S PE 650
B18 has lowest Junction damage with various annealing techniques
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 16
X-TEM of Self Amorphizing with B18H22(GIST IWJT2006)
as-implanted 250eV 1E15 B equiv. after excimer laser anneal
Flat surface
(a) Uniform Si interface at amorphous layer;
(b) Post-anneal Si re-crystallization without defects
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 17
Amorphous Layers Created by 1E15 implants of B18Hx
+ and C16Hx+ Ions
(a): X-TEM of a 1e15, 500eV per boron B18Hx (b): X-TEM of a 1e15, 3keV per carbon C16Hx+
implant yielding a 6.2nm amorphous layer implant yielding a 14nm amorphous layer
(a) (b)
Surface
Surface
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 18
5nm
X-TEM of as-implanted(Fujitsu IWJT2006)
B10Hx B18Hx B w/ Ge-PAI
Amorphous-silicon crystal interface of B10 and B18 cases are smooth while Ge-PAI indicate rough interface and small defects are observed.
(GIST, IWJT2006)
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 19
BF2 EOR Damage - TEM
EOR damage
Laser anneal SPE anneal
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 20
Plan View TEM’s of B18H22-implanted samples after various anneals
No EOR Defects Visible
(a) 650C SPE anneal (b) 720C SPE anneal 1075C spike anneal
Klaus Funk, Einladung zum RTP- & Ionenimplantations-Nutzergruppen-Treffen,Villach, Austria, September 25-26, 2006.
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 21
X-TEM of 950C, 5s Annealed Samples after B18Hx+
and C16Hx+ Co-Implants showing no EOR Defects
20 nm scale 5 nm scale
X-TEM images after 1e15 cm-2, 3keV C16Hx+ + 0.5keV B18Hx
+ implants followed by a 5s, 950C spike anneal.
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 22
B18H22 X-TEM with various anneals(JOB & NEC, IWJT2006 & SST2006)
(a)
(b)(c)
(d)
(a) B18H22 6.2nm self-amorphous layer (as-implanted)
(b) SPE with no EOR damage
(c) Laser with no EOR damage
(d) Flash with no EOR damage
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 23
SIMS Boron Depth profile
1E+18
1E+19
1E+20
1E+21
1E+22
0 10 20 30 40 50
nm
Ato
m/c
m3
B:500eVB:500eV Ge-PAIB18H22:10keVB18H22:10keV Ge-PAI
B18H22 with 6.2nm of Self-Amorphization
Boron 500eV 1E15/cm2 equivalent (PAI: Ge 5KeV 5E14/cm2) Xj @1E18
B 25.2nm
B18 19.1nm
B + PAI 17.8nm
B18 + PAI 16.1nm
B18 Self-Amorphization helps to make Shallower Junction and Eliminate the need of Ge-PAI
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 24
Cabron Cluster Implantation for B Diffusion Control(SemEquip IIT2006)
Reduction of boron diffusion during anneal
Improvement of junction abruptness
Increase in boron solubility in the active junction volume
1E+15
1E+16
1E+17
1E+18
1E+19
1E+20
1E+21
1E+22
0 10 20 30 40 50 60Depth (nm)
Con
cent
ratio
n (a
tom
s/cc
)
as-implanted
1050 C _ no Carbon
1050C _ 3keV Carbon
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 25
as-implanted SIMS Profiles: C16 vs. Ge PAI
Abrupt junction with C16 with co-implants
B18 with co-implant BF2 with co-implant
1E+15
1E+16
1E+17
1E+18
1E+19
1E+20
1E+21
1E+22
0 200 400 600 800DEPTH (Å)
B C
ON
CEN
TRA
TIO
N (a
tom
s/cc
)
B18
B18 + C16
B18 + Ge
B18 + C16 + Ge
B
as-implanted samples
1E+15
1E+16
1E+17
1E+18
1E+19
1E+20
1E+21
1E+22
0 200 400 600 800DEPTH (Å)
B C
ON
CEN
TRA
TIO
N (a
tom
s/cc
)
BF2
BF2 + C16
BF2 + Ge
BF2 + C16 + Ge
B
as-implanted samples
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 26
B18 – 500eV, 1e15 (FLASH ANNEAL)SE + J. Gelpey, Mattson
Sheet Rho
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Spike 1000C
Spike 1025C Spike 1050C Ti_750C_Tpk_1050C
Ti_750C_Tpk_1250C
Ti_900C_Tpk_1050C
Ti_900C_Tpk_1250C
Ti_900C_Tpk_1300C
Ti_900C_Tpk_1350C
Ti_1000C_Tpk_1250C
Ti_1000C_Tpk_1300C
Implant Species
Shee
t Rho
(Ohm
/Sq)
B18
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 27
Flash anneal : Rs Results(SE + J. Gelpey, Mattson)
Sheet Rho
0
400
800
1200
1600
2000
2400
2800
3200
3600
4000
B18 B18 +C16
B18 + Ge B18 +C16 + Ge
BF2 BF2 +C16
BF2 + Ge BF2 +C16 + Ge
Implant Species
Shee
t Rho
(Ohm
/Sq)
f_Spike_900C
flash_Ti_900C_Tpk_1250C
flash_Ti_1000C_Tpk_1250C
flash_Ti_1000C_Tpk_1300C
flash_Ti_900C_Tpk_1350C
f_Spike_1050C
Lower Rs is observed for f-spike 1050C and flash-Ti_900C_Tpk_1350C.
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 28
Rs. Xj Product : measure of active carrier concentration (SE + J. Gelpey, Mattson)
Rs. Xj product (inverse of active carrier concentration) is lowest for B18 implant indicating a higher active carrier concentration in the active junction area.
Rs. Xj
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
B18 B18 +C16
B18 + Ge B18 +C16 + Ge
BF2 BF2 +C16
BF2 + Ge BF2 +C16 + Ge
Implant Species
Rs.
Xj
(Ohm
/Sq.
nm
)
f_Spike_900C
flash_Ti_1000C_Tpk_1300C
flash_Ti_900C_Tpk_1350C
f_Spike_1050C
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 29
5nm
X-TEM C16 (3keV) + B18 (0.5keV) @1e15 atoms/cm2
950oC , 5 sec – annealed NO EOR DAMAGE
20nm scale 5nm scale
No EOR damage is seen with TEM for 950oC 5 sec anneal
SurfaceSurface
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 30
5nm
X-TEM C16 (3keV) + B18 (0.5keV) @1e15 atoms/cm2
Various Anneal Temperatures : NO EOR DAMAGE
950oC
No EOR damage is seen with TEM
Surface
Surface
1025oC 1075oC
Surface
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 31
Carbon Implant + SPER for e-Si:C in NFETsYaocheng Liu et al., IBM (VLSI 2007)
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 32
ClusterCarbon for Stress: Raman – C16H16 @3e15
Raman Spectra - C16H16
0
100
200
300
400
500
600
700
800
508 510 512 514 516 518 520 522 524 526 528 530
Wavenumber (cm-1)
Inte
nsity
(a.u
)
C16_6k_3e15_650C_A6
C16_6k_3e15_750C_A10-2
C16_6k_3e15_850C_A14-1
Reference_Si (scaled)
7.01 Gdynes/cm2
6.93 Gdynes/cm2
6.65 Gdynes/cm2
C16@3e15 dose, the avg. stress values for the temp. range more or less remain the same.
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 33
ClusterCarbon for Stress: Raman – C7H7 @3e15
Raman Spectra - C7H7
0
200
400
600
800
508 510 512 514 516 518 520 522 524 526 528 530
Wavenumber (cm-1)
Inte
nsity
(a.u
)
C7_6k_3e15_650C_B5-1
C7_6k_3e15_750C_B8-2
C7_6k_3e15_850C_B11-2
Reference_Si(scaled)
5.96 Gdynes/cm2
7.56 Gdynes/cm2
7.08 Gdynes/cm2
@3e15 dose, the avg. stress values for the temp. range lie within ± 15% of each other
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 34
ClusterCarbon: Stress Data
Raman Scattering (C16H10 & C7H7) (UV Laser 363.8nm)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
6k_1
e15_
650C
6k_3
e15_
650C
6k_5
e15_
650C
6k_1
e15_
750C
6k_3
e15_
750C
6k_5
e15_
750C
6k_1
e15_
850C
6k_3
e15_
850C
6k_5
e15_
850C
6k_1
e15_
650C
6k_3
e15_
650C
6k_5
e15_
650C
6k_1
e15_
750C
6k_3
e15_
750C
6k_5
e15_
750C
6k_1
e15_
850C
6k_3
e15_
850C
6k_5
e15_
850C
Implant & Anneal
Res
idua
l Str
ess
(GD
yne/
cm2)
C16H10 - 6keV C7H7 - 6keV
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 35
SummaryDue to collective effects, amorphization during cluster implantation yields powerful process advantages using low thermal budget anneals:
More complete crystal regrowth lowers defect density
Lower defect density reduces junction leakage
Active carrier concentration is increased
Channeling reduction results in shallower, more abrupt junctions without Ge PAI
3-5X increase in wafer throughput for high dose, low energy processes without risk of energy contamination
Carbon clusters are effective at creating e-Si:C with increased activation of substitutional carbon during SPER, resulting in higher tensile stress than achievable with monomer carbon implants
Junction Technology Group Presentation at SemiCon West , San Francisco, CA, July 19, 2007 36
Acknowledgements
SemEquip: Dale Jacobson, Wade Krull, Bob Milgate, Karuppanan Sekar, Jeff Buda, Brian Haslam
Mattson: Jeff Gelpey
Axcelis: Mike Ameen, Mark Harris