INCREASED EFFICIENCY OF SILICON LIGHT-EMITTING-DIODES IN A STANDARD 1.2-MU-M SILICON COMPLEMENTARY METAL-OXIDE-SEMICONDUCTOR TECHNOLOGY

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.