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