Preparation of Optoelectronic Devices Based on AlN/AlGaN Superlattices
Abstract
We present results on growth and fabrication experiments of AlN/AlGaN superlattices for ultraviolet "UV" optoelectronic devices. Superlattices with extremely short periods have been studied. The AlN ?barrier? layers are 0.5 nm thick, and the AlxGa1-xN ?wells? are 1.25 nm thick, with x ~ 0.08. This combination gives an average AlN mole fraction of 0.63 across one full period. The superlattice periods, AlN mole fractions, and energy gaps are determined using TEM, X-ray diffraction, and optical reflectance. They are all consistent with each other. For device fabrication, p-i-n structures are grown doped with Si "n-type" and Mg "p-type". The acceptor activation energy of ~ 0.2 eV is found. Mesa structures are plasma etched using chlorine chemistry. Etch rates of AlN are ~ 1/3 those of GaN under identical circumstances. Etch rates of 250 nm/min are used for the device structures. A light emitting diode, with primary emission at 280 nm is reported, and a detector with sensitivity edge at 260 nm are reported.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2002
- Accession Number
- ADA471059
Entities
People
- A. Chandolu
- B. Borisov
- G. Kipshidze
- H. Temkin
- Jongyeon Yun
- K. Zhu
- M. Holtz
- S. A. Nikishin
- S. N. Chu
- V. Kuryathov
Organizations
- Texas Tech University