Lw. Snyman et al., INCREASED EFFICIENCY OF SILICON LIGHT-EMITTING-DIODES IN A STANDARD 1.2-MU-M SILICON COMPLEMENTARY METAL-OXIDE-SEMICONDUCTOR TECHNOLOGY, Optical engineering, 37(7), 1998, pp. 2133-2141
Scaled versions of a variety of silicon light-emitting diode elements
(Si LEDs) have been realized using a standard 1.2-mu m, double-polysil
icon, double-metal, n-well CMOS fabrication process. The devices opera
ted with a n(+)p junction biased in the avalanche breakdown mode and w
ere realized by using standard features of the ORBIT FORESIGHT design
rules. The elements emit optical radiation in a broad band in the 450-
to 850-nm range. An emitted intensity (radiant exitance) of up to 7.1
mu W/cm(2) (or about 8 nW per 60-mu m-diam chip area) has been obtain
ed with 5 mA of current at an operating voltage of 18.5 V. Excellent u
niformity in emission intensity of better than 1% variation was obtain
ed over areas as large as 100x500 mu m. A best power conversion effici
ency of 8.7 x 10(-8) and a quantum efficiency of 7.8 x 10(-7) were mea
sured. All of these values are about one order of magnitude better tha
n previously reported values for Si LED avalanche devices. Coupling be
tween the elements as well as electro-optical coupling between an elem
ent and an optical fiber was realized. (C) 1998 Society of Photo-Optic
al Instrumentation Engineers.