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© 2010 Confidential & Proprietary 1
Silicon-Based GaNHigh-Power LED
Sonny WuChairman & CEO
© 2010 Confidential & Proprietary
July 14, 2010
© 2010 Confidential & Proprietary 2
LatticePower Vision
• World’s only GaN/Si-based LED production company
• Disruptive silicon technology
– Managing the challenges in GaN/Si
– Scaling to 6-inch wafers and larger to drive down costs
– Leveraging low-cost semiconductor IC standard tools for manufacturing
• Vertically integrated for scale and lighting solutions
© 2010 Confidential & Proprietary 3
Carrier substrate
TS: Transparent Substrate
TF: Thin Film
Solving GaN-on-Silicon Challenge
• Mature technology
• High material quality
• Dominates LED business
Sapphire
• Mature technology
• High material quality
SIC
• Easy to go to 6–12 inch
• Less expensive
• Easy substrate lift-off for thin film (TF) process
• Can take advantage of low-cost IC manufacturing
• Substrate lift-off is difficult
• More difficult to go to 6–12 inch
• Expensive• More difficult to go
to 6–12 inch
• Lower material quality• Tensile strain can cause
film cracking
Silicon
Challenges
© 2010 Confidential & Proprietary 4
100um100um
Managing the Stress in GaN/Si
• Lattice constant mismatch• Thermal expansion
mismatch• High tensile strain• Cracking everywhere
• Pre-patterned substrate• Proprietary multiple-layer
buffer design• <5E18 dislocation density• High material quality
© 2010 Confidential & Proprietary 5
Wet etch removal of (111) Si substrate
Sufficient n-GaNthickness
Multiple QWdesign
Optimizing epi and Device
• High-quality thick n-GaN layer to minimize defects
• Multiple QW design to maximize internal quantum efficiency
• High-efficiency epi
• Thin film structure with proprietary process to maximize the light extraction
• High-performance device
After epi growth, GaN LEDstructure on (111) Si substrate
carriercarrier
P-contact reflector metal and bonding metal deposition and wafer bonding
N-side ohmic contact and top surface roughening
© 2010 Confidential & Proprietary 6
Performance of 1mm Chip
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DC Drive Current (mA)
Ligh
t out
put (
mW
)
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Light output (mW)
Vf (V)
Achieving High Performance
• >50% EQE at operating current, on par with sapphire-based LEDs
• Low operation voltage of 3.1–3.4V
• 110 lm at 350mA white (5000K CCT, 65 CRI)
EQE Curve of 1x1mm Chip
Typical Operation current
0.01 0.1 1 10 100
J/A*cm-2
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10%
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30%
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60%
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80%
EQ
E
0%
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EQ
E
Typical Operation Current
White LED-based on GaN on Silicon110 lm at 350mA
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0 200 400 600 800Current (mA)
Whi
te li
ght i
nten
sity
(lm
)
© 2010 Confidential & Proprietary 7
Proving Reliability and Manufacturability
• Highly stressed lifetest at 3x normal operating current and 110–120 junction temperature
• Reliability similar to LEDs made on sapphire
• Silicon-based LED manufacturing process control; yield similar to sapphire-based LEDs
© 2010 Confidential & Proprietary 8
LatticePower’s LED Light Bulb
Specifications
Product name Snowcone
Voltage (V) 110 VAC
Power consumption 7W +/−10%
Power factor 0.95
Luminous flux (lm) 700 lm (neutral white), 480 lm (warm white)
Efficacy 92 lm/W (neutral white), 66 lm/W (warm white)
Color temperature 5000k +/−10% (neutral), 3000k +/−10% (warm white)
CRI 67 (neutral white), 80 (warm white)
Lifetime 40,000 hr
Weight & dimension 170g, 60mm x 122mm
Price $8 @ minimum 1 million order
© 2010 Confidential & Proprietary 9
LatticePower’s Ambition
Haitz’s Law
Timeline Today 2012 2015
Efficacy 100 lm/W 120 lm/W 150+ lm/W
Cost Base −50% −80%
6-inch-diameter and larger silicon wafer technology :Impact of falling cost on Haitz’s law
6″ wafer� �
8″ wafer
© 2010 Confidential & Proprietary 10
LED Light Bulb Adoption
Key Factors for Lower Cost
• Silicon-based LED chips
• High-efficiency LED driver
• Scale and low-cost manufacturing capability
7W LED 10W LED
Timeline Today 2012 2015
Efficacy 70 lm/W 90 lm/W 120 lm/W
7W/45W ASP $30 $8 $4
10W/60W ASP – $12 $6
Si wafer size 50mm/2″ 150mm/6″ 200mm/8″
© 2010 Confidential & Proprietary 11
Contributors:Bo Lu, Jiang Fengyi, Wangli, Wang Xiaolan, Zhou Yinghua, Tang Yingwen, Liu Junlin, Yan Zhanbiao, Chen Haiying, Zheng Changda, Xiong Chuanbing, Mo Chunlan, and Sonny Wu.
Acknowledgements
© 2010 Confidential & Proprietary 12
Thank You!
LatticePower ( 晶能光电晶能光电晶能光电晶能光电)
www.latticepower.com
Contact: [email protected]