DEFECT SELECTIVE ETCHING OF THICK ALN LAYERS GROWN ON 6H-SIC SEEDS - A TRANSMISSION ELECTRON MICROSCOPY STUDY

Conference · Tue Jan 01 04:00:00 EST 2008

OSTI ID:937133

Nyakiti, Luke ^[1]; Chaudhari, Jharna ^[1]; Kenik, Edward A ^[2]; Lu, Peng ^[3]; Edgar, J H ^[3]

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1. Texas Tech University, Lubbock
2. ORNL
3. Kansas State University

In the present study, the type and densities of defects in AlN crystals grown on 6H-SiC seeds by the sublimation-recombination method were assessed. The positions of the defects in AlN were first identified by defect selective etching (DSE) in molten NaOH-KOH at 400 C for 2 minutes. Etching produced pits of three different sizes: 1.77 m, 2.35 m , and 2.86 m. The etch pits were either aligned together forming a sub-grain boundary or randomly distributed. The smaller etch pits were either isolated or associated with larger etch pits. After preparing crosssections of the pits by the focused ion beam (FIB) technique, transmission electron microscopy (TEM) was performed to determine which dislocation type (edge, mixed or screw) produced a specific etch pit sizes. Preliminary TEM bright field and dark field study using different zone axes and diffraction vectors indicates an edge dislocation with a Burgers vector 1/3[1120] is associated with the smallest etch pit size.

• Research Organization: Oak Ridge National Laboratory (ORNL); Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 937133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Aluminum nitride
BURGERS VECTOR
CROSS SECTIONS
DEFECTS
DIFFRACTION
DISLOCATIONS
EDGE DISLOCATIONS
ETCHING
ION BEAMS
SEEDS
TRANSMISSION ELECTRON MICROSCOPY
VECTORS
dislocations
etch pits
transmission electron microscopy