Transcript UV LED

高功率紫外光氮化鋁銦鎵發光
二極體之研製
100-2622-E-006-024-CC3
Reporter : 成大微電子所張守進
合作企業 : 新世紀光電
email: [email protected]
2000’s Illumination
70’s Indicators
(DIM LED)
80’s Signs
(Multi-Color LED)
90’s Displays
(Full-Color HB LED)
Color + White
HB + HP LED
2nd half 2000’s
General Lighting
(“SUPER” LED ?)
White
Applications of high-brightness LEDs
•
Signaling
 Indicators (lamp, numeric,…)
 Automotive (interior, exterior)
 Traffic lights
 Display (indoor/outdoor)
•
Illumination
 Backlighting
 Sign & decorating lighting
 Specialty lighting (flashlight,...)
 General illumination (2-5 more years)
Applications of high-brightness LEDs
Colored light in sign
LED Lighting in demo. room
Large-area outdoor display
Landscape lighting
Colored light in display window
可見光LED:中國大陸大量擴產
供過於求,利潤低
(Lighting??)
UV LED: 技術門檻相對高
(large leakage current,
poor crystal quality)
 Niche
Application of UV LEDs
•UV Curing
•Bio
•Synthesis of Vitamin D
•Free-Space Communications
…….
Introduction : High Power UV LED
Technology
Nichia (385 nm)
LedEngin (365 nm)
Luminus Devices (390 nm)
SETI (240 – 400 nm)
Characteristically narrow, well-defined output
Enfis (395 nm module)
In0.05Ga0.95N/GaN MQW  In0.05Ga0.95N/AlGaN MQW
Ni/Au semi-transparent
layer
Mg:GaN
Mg:Al0.15Ga0.85N
InGaN/GaN
MQW
Mg:GaN
Mg:Al0.15Ga0.85N
n-electrode
Ti/Al/Ti/Au
InGaN/AlGaN
MQW
Si:GaN
Al2O3
Ni/Au semi-transparent
layer
nucleation layer
n-electrode
Ti/Al/Ti/Au
Si:GaN
Al2O3
nucleation layer
Poor quality for In0.05Ga0.95N/Al0.18Ga0.82N MQW
In0.05Ga0.95N/Al0.1Ga0.9N MQW LED
Intensity (a.u.)
In0.05Ga0.95N/Al0.18Ga0.82N MQW LED
-6000
InGaN/GaN MQW LED
15 nm
-3
-4000
+1
-1
-2
-2000
0
2000
Relative Diffraction Angle (arcsec)
5
PL intensity (a.u.)
InGaN/Al0.1Ga0.9N MQW LED
4
InGaN/Al0.18Ga0.82N MQW LED
InGaN/GaN MQW LED
3
2
1
0
300
400
500
600
Wavelength (nm)
700
Output Power (mW)
10
8
6
4
InGaN/Al0.1Ga0.9N MQW LED
2
0
InGaN/Al0.18Ga0.82N MQW LED
0
50
InGaN/GaN MQW LED
100
150
200
250
Current (mA)
300
Energy band diagram
ΔE1
ΔE2
Al0.1Ga0.9N=
3.781 eV
In0.05Ga0.95N=
3.394 eV
GaN=3.42 eV
Experiment
p-GaN
MQW
n-GaN
Buffer layer:
1)MOCVD AlN buffer
2)Sputtering AlN buffer
Sapphire Substrate
Advantage for Sputtering AlN buffer:
1)Easy to Growth
2)Time Saved
3)Better quality
4)Better Uniformity
(002) And (102) XRD spectra of GaN with high temperature
PVD AlN and LT GaN buffer on flat sapphire substrate
LT-G a N buffe r
S putte r-A lN buffe r
FWHM
76.3
104
233.8
103
102
LT-G a N buffe r
FWHM
381.7
450.7
103
I n te n s ity ( c p s )
105
I n te n s ity ( c p s )
S putte r-A lN buffe r
102
101
101
-2000
-1500
-1000
500
0
-500
O M EG A _R EL (a rc se c )
(002)
1000
1500
2000
-2000
-1500
-1000
-500
0
500
O M EG A _R EL (a rc se c )
(102)
1000
1500
2000
(002) And (102) XRD spectra of GaN with high temperature
PVD AlN and MOCVD AlN buffer on patterned sapphire
substrate
002 Rocking Curve
102 Rocking Curve
MOCVD AlN buffer
Sputtering AlN buffer
Intensity (a.u.)
Intensity (a.u.)
MOCVD AlN buffer
Sputtering AlN buffer
16.9
17.0
17.1
17.2
17.3
17.4
scan (degree)
FWHM
Sputter:239.9
MOCVD:349.9
17.5
17.6
23.8
24.0
24.2
24.4
scan (degree)
FWHM
Sputter:240.9
MOCVD:429.9
I-V characteristics of UV LEDs with
sputtered AlN nucleation layer
(a) forward I-V and (b) reverse I-V characteristics of GaNbased UV LEDs. Here the “ESAN” and “IGN” stand for the
ex-situ sputtered AlN and the in-situ GaN nucleation LED,
respectively.
Relationship of emission wavelength and 20mA
output power of UV LEDs with and without AlN
nucleation layer
Measured light output power as a function of the entire emission peak
wavelength of UV LEDs. The Inset is the output power enhancement ratio of exsitu AlN nucleation to in-situ GaN nucleation at 20 mA.
Reliability of the UV LEDs with
AlN nucleation layer
power output (a) and reverse leakage current (b) reliabilities
of UV LEDs with in-situ GaN nucleation and ex-situ sputtered
AlN nucleation.
Summary
•Use Al0.1Ga0.9N quantum barrier to replace
conventional GaN barrier 
better crystal quality, lower leakage current,
improve LED performances
•Use sputter AlN nucleation layer 
high productivity, better crystal quality,
improved LED performances
新世紀光電
http://www.gpiled.com/web/page
s/products/gv-x
Thank You
Q&A?