2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
SiC activities at Linköping University
A. Henry and E. Janzén
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
SiC : Prof. Erik Janzengrowth (bulk and epi)defect and characterisation
Nitride : Prof. Bo Monemargrowthoptical characterisation
Electronic Structure :Prof. L. Johanssonphotoemission
Compound Semiconductors : Prof. Per-Olof Holtzoptical characterisation
Spintronic : Prof. Weimin ChenMagneto-optic measurements
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
GrowthBulk
Sublimation High temperature CVD
EpitaxyHorizontal Hot Wall CVDVertical Hot Wall CVDSublimation EpitaxyLPE
Simulation
CharacterizationOptical
PL, PLE, Time resolved PL, FTIR, FTPL, CL
ElectricalHall, IV, CV, DLTS, MCTS
Magnetic resonanceODMR, EPR
StructuralXRD, Lang topograph
Theoretical calculation
SiC activities
S-Science : Sensor applicationThin Film : TEM………
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
JunctionTermination
Passivation
Contacts
n
p
Active layer2.5kV : 30 µm thick
n- 1.5E15 cm-3
High-Power diode
N+ Substrate
SiC diodes
Si IGBTs
CVD
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
Horizontal Hot-Wall CVD epilayer
Quartz tubeInsulation
Substrate
Coil
Gas InletH2 carrierSiH4 + C3H8Doping (N2 , TMA …)
Growth Temperature:1600 oC in horizontal
Growth Pressure:50 - 1000 mbar
O. KordinaC. Hallin : surf. prep., precursorU. Forsberg :MESFETÖ. Danielsson :Simulation
Graphite
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
Simulation
0 20 40 60 80 1000
1
2
3
4
5
6
Position along gas flow direction (mm)
Gro
wth
rate
(µm
/h)
1 2 3 4
1000 mbar13 l/min
0.4 0.6 0.8 1.0 1.2 1.4 1.6
1017
1018
D
opin
g co
ncen
tratio
n (c
m-3)
Inlet C3H8 flow (ml/min)
Si-face C-face
1.0 2.0 3.0 4.0 5.0 C/Si ratio
0.4 0.8 1.2 1.6 2.0
1018
1019
1020
D
opin
g co
ncen
tratio
n (c
m-3)
Inlet SiH4 flow (ml/min)
Si-face C-face
0.4 0.8 1.2 1.6 2.0 2.4Inlet C3H8 flow (ml/min)
Temperature Growth Rate
N Doping
Ö. Danielsson
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
Degradation : Drift of the forward current
2 2,5 3 3,5 4 4,5Va[V]
0
50
100
150
200
Ja[A
/cm
2]
Virgin deviceIntermediateStressed
Creation and expansion of stacking faults
X-ray TopographyCathodoluminescenceCL
P. Bergman
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
380 400 420 4400
1
2
3
4
5
6 x 104
Photon Wavelength (nm)
PL
Inte
nsity
Normal Spectra New Defect Emis s ion
Low Temperature PLCathodoluminescenceCL
X-ray Topography
PL at 77KLang topo [1,-1,10]P. Bergman
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
Today (2 inch diam)Thickness typically 30-40 µm (80 µm)
Unif = σ/mean < 8%Background doping level n-type (nitrogen) 1-2E14N-doping 1E15 – 5E18 Unif < 20%Al-doping 5E15 – 1E19 Unif <20%Typical lifetime (35 um, 2E15) > 250 µs
Future work related to SiC-CVD- Degradation : reduction of critical defects - Lifetime limiting defects- growth on “non-standard” surface- δ-doped layers- Regrowth- Other dopant : P, As, B, V…
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
High Temperature CVD Bulk
RF Coil
SeedHeater
GraphiteFoamQuartz tube
Gas InletHelium carrierSiH C H4 2 4+
1111
Seeded Sublimation Growth
RF Coil
Source
Crucible
InsulationSeed Crystal
O. KordinaA. Ellison
T process:2100 – 2300 C
HTCVD advantages: high vacuumhigh purity of the sources gasescontinuous supply of the source materialpossibility to adjust C/Si
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
SiC MESFET withPURER SUBSTRATE
(HTCVD)(80 V STRESS)
0 10 20 30 400
10
20
30
404522MESFET 1×100 µm
∆VGS = -2 V/step Light ON Light OFF
VGS = 0 V
IDS (VDS)
I DS (
mA)
VDS (V)
0
5
10
15
20
25
30
0 10 20 30 40
Vds (V)
Id (m
A)
Vgs=0V , -2V/step
Degradation of I-V static characteristics
ECSCRM 2000 + JESICA PROJECTC. Brilinski
SiC MESFET withCommercial S.I. substrate
High Frequency Device
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
2-inch diameter 4H-SiC substrates pilot products
SIon- and off-axis
N+off-axis
P+off-axis
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
Future work related to HTCVD
Characterization : - identification of defects in SI SiC and understand their properties - Support to Okmetic (SI, N and P substrates)
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
CharacterizationMost studied defects in SiC after irradiation / implantation and annealing
(2 MeV – T>1200 C)
2900 2920 2940 2960 2980
Photon Energy (meV)
PL in
tens
ity (a
rb.u
nits
)
PL PLE
L1
M1
1
series limit
2S 3S
L1
1S
62 meVEC
4SS-likeP -like0
P -like+/-
4H-SiC
D1 : Speudo-donor Z1,2
DLTS (e lectron trap)
MCTS (hole trap)
100 200 300 400 500
4H-SiC
Z½EC-0.68 eV
HS1EV+0.35 eV
Temperatu re (K)
∆C/C
(ar
b. u
nits
)
Optical Electrical
(T. Egilsson) (L. Storasta)
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
1 0Annealing temperature (°C)0 500 1000 1500 2000
10
10
10
10
10
10
10
10
10 10 10 10
10
10
10
10
4H SiC
PL L /Q
Z (
cm
)1
/2
-3H
S1 (
cm)
-3PL
L/Q 1
0
DLT
S &
c
on
cen
trat
ion
(cm
)-
3M
CTS
+
-Association
D1 HS1
CB
VB
1s2s, 2p
2.9 eV
62 meV
L1
0.35 eVHS1
(L. Storasta)
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
CharacterizationDefect study : Atom displacementC : 90 keVSi: 220 keVFace dependent ?
160 240 320 540 660
EH6EH3
Z1/2
EH1
HS2
DLTSMCTS
Hol
e tra
psEl
ectro
n tra
psD
LTS/
MC
TS s
igna
l (ar
b.un
its)
Temperature (K)
N-type 2.5E15 cm-3 epiLow energy electron irradiation80-300 keV
L. Storatas
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
150 200 250 300
EH6EH3
Z1/2
EH1
HS2
Intro
duct
ion
rate
(arb
.uni
ts)
Irradiation energy (keV)
Si-face 4H epilayer
100 120 140 160 180 200 220
1
10EH1, EH3, Z1/2
HS2
C/S
i fac
e co
ncen
tratio
n ra
tio
Irradiation energy (keV)
L. StoratasC related centers
2003-05-18..20 A. Henry – 2nd RD50
Department of Physics and Measurement TechnologyMaterial Science
• Photoluminescence
4260 4280 4300 4320 4340 4360 4380 4400 4420
104
105
a1
b1
c1
d1c2
e1g1
g2L1
a1b1
c1
d1
c2e1g1g2
L1
f1
Si-side
C-side
TEM electrons 120keV
log(
PLIn
tens
ity) (
a.u.
)
Wavelength ( Å)
C-Side
Si-Side
Wavelength (Å)
4300 4350 4400 4450 4500 4550
10 3
10 4
10 5
a1
b1
b1(78meV)
b1(78meV)
c1
d1 d1 phonon band
c2e1
g1
g2
L1
a1
b1
c1d1
c2e2
e1
g1
g2
L1
c1 phonon band
b1 phonon band
b1 phonon band
PCB990 10 min TEM irradiation 160keV
Wavelength (Å)
PL In
tens
ity (a
.u.)
Si-side
C-side
4H-SiCT=2K
C-Side
Si-Side
4260 4340 4420Wavelength (Å)
4300 4440 4500
PL In
tens
ity (a
.u.)
PL In
tens
ity (a
.u.)
120 keV 160 keV
F. Carlsson