The epitaxial layer quality of AlxGa1-xN (x>0.6) on sapphire substrate grown by metal organic chemical vapor
deposition (MOCVD) needs to be further improved. In this paper, we evaluated the properties of defects, lattice
mismatch between epitaxial layer and substrate, crystal quality and conductivity for these high Al mole fraction
materials from the viewpoint of fabricating high performance solar blind detectors by comprehensive utilizing
various undamaged measurements. The measurement of transmission spectrum was used to evaluate the absorption
edge, band gap, mole fraction of Al content, hetero-epitaxial interface, and transmissivity in the ultraviolet spectral
range. X-ray diffraction (XRD) was used to measure the component of the AlGaN material, uniformity of the
material and crystal quality. The conductivity of the surface layer of the AlGaN film material was obtained by using
high precision current-voltage curve measurement. In short, the material quality, optical and electrical properties,
and uniformity for high Al mole fraction AlGaN epitaxial layers were qualitatively or quantitatively measured and
analyzed. These works lay the foundation for manufacturing high performance solar blind ultraviolet detectors
based on high Al mole fraction AlGaN epitaxial materials on sapphire substrate.
The etching process has great influence on the performance of solar blind detector based on AlxGa1-xN epitaxial
layers on sapphire substrate with high Al mole fraction grown by metal organic chemical vapor deposition
(MOCVD) method. Traditional etching methods, including wet or reactive ion etching (RIE) are hard to achieve
good result due to the high chemical-stability of AlGaN films with high Al mole fraction. In this paper, we studied
on the inductively coupled plasma reactive ion etching (ICP-RIE) of high Al mole fraction AlxGa1-xN films (x>0.4)
for fabricating high performance solar blind detectors. SiN was used as mask, and Cl2 and BCl3 were used as
etching gas. Etching systems was selected from Oxford Inc. DC bias was controlled automatically. A 2.5:1 of
selectivity on AlGaN and SiN was obtained with suitable flux and component of etching gas, RF power and ICP
power. Etching velocity was adjusted mainly by RF power. The role of Ar, Cl2, and BCl3 in the etching process was
also discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.