Title: Nitride Growth using Buffer Layers The Pretty Complete Story
1Nitride Growth using Buffer Layers The Pretty
Complete Story
- Ted Wangensteen
- EEL 6935
- WBG I
- Spring 2003
2Outline
- Introduction Why Nitrides?
- Literature Review
- Growth Background Problems encountered
- Improvements, in-situ Methods - Results
- Summary
3Why Nitrides?
- High Temp/Chem/Radiation Resistant Material
- Blue and UV LEDs , Blue completes the Color
Spectrum - High output, Lower Cost Lighting, i.e.
Stoplights, Dashboards - UV Photodectors
- Short Wavelength Laser gt Increase Optical
Memory Storage
4Cutting Wavelength in Half - Quadrupules Data
Storage Capability
5References
- Nakamura, Shuji, Blue Laser Diode, The Complete
Story , (2000), Springer. - Ponce, Fernando, Crystal Defects and Device
Performance in LEDs and LDs, Introduction to
Nitride Semiconductor Blue Lasers and Light
Emitting Diodes, Chapter 4, Nakamura, Ed., Taylor
and Francis, (2000). - DenBaars, S, Basic Physics and Materials
Technology of GaN LEDs and LDs, Chap. 1, Ibid. - Akasaki, I., Progress and Prospects of Group
III Nitride Semiconductors, Blue Laser and Light
Emitting Diodes III, (1998), Ohmsha, Japan. - Wangensteen, T. , Pankove, J. ., GaN Growth,
Astralux, Inc., Boulder, CO., (1999).
6Nitride Growth Issues
- Cleaning, Preparation want Clean, Flat Surfaces
- Doping difficult due to Int. Carrier
Concentration - Ohmic Contacts
- Large Scale Substrates Unavailable- nec. For
Manu. - Biggest Problem is Lattice/Thermal Mismatch of
Substrates Example-GaN/Sapphire-Blue Diode
7Ponce, Fernando, Crystal Defects and Device
Performance in LEDs and LDs, Introduction to
Nitride Semiconductor Blue Lasers and Light
Emitting Diodes, Chapter 4, Nakamura, Ed., Taylor
and Francis, 2000.
8Ponce, Fernando, Crystal Defects and Device
Performance in LEDs and LDs, Introduction to
Nitride Semiconductor Blue Lasers and Light
Emitting Diodes, Chapter 4, Nakamura, Ed., Taylor
and Francis, 2000.
9- Ponce, Fernando, Crystal Defects and Device
Performance in LEDs and LDs, Introduction to
Nitride Semiconductor Blue Lasers and Light
Emitting Diodes, Chapter 4, Nakamura, Ed.,Taylor
and Francis, 2000.
10Example of Nitride Growth effect on development
of the Blue DiodeHistorical milestones (very
condensed version)
- -Proof of Concept, Potential for development
- Luminescence - Pankove, Maruska ( 1970 )
- 1st Blue LED Metal-Insulator-Semiconductor
Pankove (1971) - gt? Key Problem was Growth GaN grows laterally -
had to wait until improved - -Process Improvements - Breakthroughs
- Buffer Layer - Yoshida (1983)
- AlN Buffer Layers Akasaki (1986)
- P-Type GaN by Low Energy Electron Irradiation -
Akasaki (1988) - gtgt Namamura says Aha!
- - Device Manufacturing
- GaN Buffer Layer Nakamura (1991)
- High Output GaN LED Nakamura (1991)
11 Akasaki, I., Progress and Prospects of Group
III Nitride Semiconductors, Blue Laser and Light
Emitting Diodes III, 1998, Ohmsha, Japan
12- Nakamura, Shuji, Blue Laser Diode, The Complete
Story , 2000, Springer.
13Nakamura, Shuji, Blue Laser Diode, The Complete
Story , 2000, Springer.
14 Akasaki, I., Progress and Prospects of Group
III Nitride Semiconductors, Blue Laser and Light
Emitting Diodes III, 1998, Ohmsha, Japan
15Nakamura, Shuji, Blue Laser Diode, The Complete
Story , 2000, Springer.
16Nakamura, Shuji, Blue Laser Diode, The Complete
Story , 2000, Springer.
17Nakamura, Shuji, Blue Laser Diode, The Complete
Story , 2000, Springer.
18 Akasaki, I., Progress and Prospects of Group
III Nitride Semiconductors, Blue Laser and Light
Emitting Diodes III, 1998, Ohmsha, Japan
19Summary
- Nitrides have variety of practical uses
- Lattice-Therm mismatch problem
- Shown Stunning Material Improvements by using a
Buffer Layer