Material Properties and Applications of Gallium Nitride (GaN)
Gallium Nitride (GaN) is a III-V compound semiconductor material which has wide band gap and high electron mobility.
• Band Gap : 3.4 eV (300 K, direct)
• Electron Mobility : 440 cm2/(V·s) (300 K)
• Thermal Conductivity : 1.3 W/(cm·K) (300 K)
Usually GaN layers are deposited using Metal Organic Chemical Vapor Deposition (MOCVD) or Molecular Beam Epitaxy (MBE). GaN can be deposited on several types of substrates such as Sapphire, Silicon or Silicon Carbide (SiC), but the cost of GaN epi process and repeatable high-quality crystal growth are challenges in GaN-based device fabrication.
GaN is an attractive material for following applications due to these unique material properties.
• Power Devices including the metal–oxide–semiconductor field-effect transistor (MOSFET) and the high-electron-mobility transistor (HEMT)
• High-brightness (HB) Light-emitting-diodes (LEDs)
• RF and microwave devices for telecommunication
• High-power blue laser diode
GaN/AlGaN Anisotropic Etching
Vertical and smooth sidewall without skirt was achieved using chlorine chemistry. There is no notches on the AlGaN bottom edge. Furthermore, there is no pillars on the entire surface.
Etch Rate : 142 nm/min
Etch Selectivity : 8.6 (over SiO2 mask)
Etch Uniformity : ±1.7 % (over the 2-inch substrate)
This highly anisotropic etch process is useful for blue laser diode fabrication.
Any questions on our process capabilities on GaN etching?
GaN Reverse Tapered Etching
For improving the external luminance of GaN-based LEDs, light escaping via the GaN sidewalls needs to be prevented.
SAMCO developed a reverse-tapered etch process of GaN using chlorine chemistry.
Reverse-tapered Angle : 70°
Etch Rate : 140 nm/min (using a Ni mask)
Reverse-tapered GaN layer on Patterned Sapphire Substrate (PSS)
Any questions on our process capabilities on GaN etching?
GaN Etching with Smooth Sidewalls
GaN films with a minimum level of crystal defects are essential for blue LED and laser diode applications. Epitaxial Lateral Overgrowth (ELO) is one method for depositing lower defect GaN films. Etching of GaN plays a critical role in GaN ELO. GaN was etched using a SiO2 mask. The etched profile showed smooth surface and sidewalls.
Etch rate : 0.3~0.4 µm/min
Photo courtesy of Hiramatsu Research Center, Department of Engineering, Mie University
System Lineup for GaN Dry Etching
RIE Systems
– Excellent GaN etch uniformity over the wafers
– Optional optical/Interferometric end-point detection
– Easy-to-use touch-panel GUI
ICP Etch Systems
– ICP plasma sources optimizing GaN etch profile control
– Optional optical/Interferometric end-point detection
– Easy-to-use touch-panel GUI
ICP Etch Systems for Batch Processing
– Process chambers accommodating multiple small wafers
– Optional optical/Interferometric end-point detection
– Easy-to-use touch-panel GUI
Featured Solutions
SAMCO has developed AlGaN/GaN etch processes for GaN power device fabrication.
Please visit our featured solution page for more detail.
