UV-Specific (320-365 nm) Digital Camera Based On a 128x128 Focal Plane Array of GaN/AlGaN p-i-n Photodiodes
J.D. Brown, J. Boney, J. Matthews, P. Srinivasan, J.F. Schetzina
North Carolina State University
Thomas Nohava, Wei Yang, Subash Krishnankutty
Honeywell Technology Center
This article was received on Wednesday, June 14, 2000 and
accepted on Thursday, July 13, 2000. Abstract
An
ultraviolet-specific (320-365 nm) digital camera based on a 128x128 array of
backside-illuminated GaN/AlGaN p-i-n photodiodes has been successfully
developed. The diode structure consists of a base n-type layer of AlGaN (~23% Al)
followed by undoped and then p-type GaN layers deposited by metal organic vapor
phase epitaxy. Double-side polished sapphire wafers serve as transparent
substrates. Standard photolithographic, etching, and metallization procedures
were employed to fabricate the devices. The fully-processed photodiode array
was hybridized to a silicon readout integrated circuit (ROIC) using In bump
bonds for electrical contact. The UV camera was operated at room temperature at
frame rates ranging from 15 to 240 Hz. A variety of UV scenes were
successfully recorded with this configuration. 