This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
The fabrication and characterization of InGaAsP/InP avalanche photodiodes for near-infrared detection is described in detail. Particular material requirements which must be satisfied for these devices are considered and the special techniques involved in the use of liquid phase epitaxy which have been developed for preparing such material will be discussed. The impact ionization coefficients in InP which are important for the design of low noise avalanche photodiodes have been experimentally determined. A special device structure consisting of an InP p-n junction for multiplication and an InGaAsP or InGaAs layer for absorption is presented which results in a substantial decrease in dark current over what is typically observed in simple InGaAsP p-n junctions.
As a result of this work, methods have been developed for the growth of compositionally uniform, high purity liquid phase epitaxal layers. It has been shown that growth must take place at a constant temperature to avoid compositionally graded layers. Baking techniques have been developed for purifying the growth solutions and the net doping levels of the n-type layers have been reduced to 1 x 10('15) cm('-3) in InP and decreases throughout the lattice matched InGaAsP alloy range to about 2 x 10('14) cm('-3) in InGaAs.
A new device structure has been devised which allows routine photocurrent measurements for illumination from either side of a p-n junction and has been used to obtain the most reliable InP ionization coefficient data yet reported. These parameters have been determined over a wider range of electric fields than has ever been reported before. It was found that the ionization rate for holes is greater than electrons by a factor of 4 at low fields (2.5 x 10('5) V/cm) and decreases to about 1.3 at high fields (7.0 x 10('5) V/cm).
The dark currents in InGaAsP avalanche photodiodes have been reduced to less than 10 nA by placing the p-n junction in the larger bandgap InP. Substantial avalanche gains, fast response times, and high quantum efficiencies have been observed in these devices. This structure appears to be very suitable for high data rate, fiber optic communications applications.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
