GaN HEMT and LED Technology,

enabled by G5/G5+

AIXTRON Taiwan User Seminar 2013

Sam Shen Process Engineer AIXTRON Taiwan

2013/10/22 P 2

Outline

Hardware evolutions in G5/G5+ reactors a. Penta injector and GMS b. In-situ clean status in G5/G5+ c. Satellite pocket profile design

GaN HEMT and LED technology a. HEMT application in G5/G5+ reactors b. LED on Si application in G5+ reactors Summary

2013/10/22 P 3

Planetary Reactor Capacity Evolution

11x2″

AIX 2600G3 HT 24x2″ / 8x4″

AIX 2800G4 HT 42x2″ / 11x4″ / 6x6″

2000

2003

2006

2010 AIX G5 HT 56x2″ / 14x4″ / 8x6″ / 5x8″

2013: AIX G5+

2011: AIX G5 HT-TM

2010: AIX 2800G4 HT

Applications on Sapphire

2013/10/22 P 4

Configurable common platform for multiwafer 8x6 inch & 5x8 inch

GaN on Si HEMT and LED applications

Automated process flow in single & dual process module

AIX G5/G5+ Planetary IC2 Platform

Integrated Concept (IC2) System with automation & dual PM

2013/10/22 P 5

1 2 3 4 5

AIX G5+ for 8” Si wafers

G5+ = 8 inch wafer configuration in G5 Key item: new injector (“Penta Inlet”) to

enable growth on 8 inch wafers 5x8 inch wafer configuration

5x8 inch

2013/10/22 P 6

L4/L2 = 50/50

L4/L2 = 100/0

L4/L2 = 0/100

Calculation L3 = 100

Depletion Growth Rate

Depletion profiles from different injection level

TEGa Calculation Case01 Case03 Case04 L4 50 50 100 0 L3 0 0 0 0 L2 50 50 0 100

Growth rate (Rotation Disc)

2013/10/22 P 7

Ease of use: PentaTune Wizard, Revision 1

+/- 1% area in spec

2013/10/22 P 8

Why use Cl2 for In-situ etching ?

Etch by 5%Cl2/ 95%N2 mixture •Etch by Cl or Cl2 radicals in N2 ambient. •AlN etching require > 600C. •Marathon test OK.

GaCl or AlCl are very volatile TSurf > 1350 °C for AlN etch by HCl TSurf > 600 °C for AlN etch by Cl2

Dissociation of Cl2 is much better than HCl

2013/10/22 P 9

Multi-step clean: Reactor status after marathon of 6 run & 7 clean – cycles (HEMT application)

prior to marathon: after marathon:

System reset between runs is enabling full proces automation

2013/10/22 P 10

Free of Cl/Cl2 residuals

(um)

AlN/AlGaN buffer

2013/10/22 P 11

New pocket design

Wafer

LED wavelength fine tuning by different pocket profile Lift-off by different heights (by sapphire spheres). Pocket design: flat/ concave/ convex recess. Concave shaped recess with 100um & 100um lift-off.

Thickness uniformity on 8” Si Std. dev. = 1.29% w/o edge exclusion

86% in ~4 nm bin

Avg. Std. deviation ~ 1.3 nm Max-min on wafer ~ 6 nm Three wafers: 86% in 4 nm bin

GaN HEMT and LED

Technology

2013/10/22 P 13

Meltback etching Ga and Si atoms have

strong reaction at high temperature ambience.

AlN layer No meltback etching.

Best candidate of buffer layer for nitride growth on silicon substrate.

AlGaN staircase Strain management. Defect density reduction.

Challenges for GaN on Si growth

2013/10/22 P 14

HEMT runs – 6 inch transfer to 8 inch

(on 8 inch wafer)

Std. dev ~ 2.1%(w/o edge exclusion)

6″ to 8″

(on 6 inch wafer)

Std. dev ~ 1.42%(with edge exclusion)

2013/10/22 P 15

AIX G5+ reproducibility of HEMT structures

All wafers within +/- 0.02 µm All in-wafers thickness max-min < 0.06um All wafers with comparable standard deviation < 1% All data without edge exclusion

Excellent on-wafer, w2w, r2r uniformity

Uniformity (std) = 0.86% XRD FWHM

400

500

600

700

800

900

1000

1100

1200

FWH

M /

arcs

ec

002 Center 002 Edge 102 Center 102 Edge

run1 run2 run3 run4 run5

2013/10/22 P 16

Carbon doped GaN: Overview

Avg. carbon level in the range of 2e18 ... 2e19 at/cm3

Adjustable uniformity/distribution of carbon level.

LED on 8 inch Si Technology

2013/10/22 P 18

PL data and EL quicktest of LED on 8 inch Si

PL dominant WL mapping

2013/10/22 P 19

R2R Data: LED on 8 inch Si using Cl2 in-situ etching

2theta / Omega

Adjust SatRot flow

Run1 Run2 Run3 Run4 Run5

2013/10/22 P 20

R2R Data: LED on 8 inch Si using Cl2 in-situ etching

• Al content run-to-run deviation < 0.5% (abs) • XRD run-to-run std. deviation < 5%

200

300

400

500

S0365 S0366 S0367 S0368 S0369

XRD

FW

HM

(arc

sec)

GaN XRD (002) FWHM all runs ( 0 0 2 ) center

( 0 0 2 ) halfway

( 0 0 2 ) edge

300

400

500

600

700

800

S0365 S0366 S0367 S0368 S0369

XRD

FW

HM

(arc

sec)

GaN XRD (102) FWHM all runs ( 1 0 2 ) center

( 1 0 2 ) halfway

( 1 0 2 ) edge

0

10

20

30

40

50

60

70

S0365 S0366 S0367 S0368 S0369

AlGaN1_CenterAlGaN1_EdgeAlGaN2_CenterAlGaN2_EdgeAlGaN3_CenterAlGaN3_Edge

Run1 Run2 Run3 Run4 Run5

Al C

onte

nt (%

)

AlGaN1

AlGaN2

AlGaN3

Run1 Run2 Run3 Run4 Run5 Run1 Run2 Run3 Run4 Run5

2013/10/22 P 21

Latest LED on 8 inch Si results

0.4 mm

SatDisc 1 SatDisc 2

Mean dom. WL 449.3 nm 449.2 nm

Std dev. 1.5 nm 1.3 nm

3 mm edge exclusion

• All satellites with integrated lift-off pins

• All wafers cracks on <1mm from edge

2013/10/22 P 22

www.aixtron.com

Sam Shen

s.shen@aixtron.com