HIGH RESPONSIVITY GAINAS PIN PHOTODIODE BY USING ERBIUM GETTERING

In this article, we grow the GaInAs layers by introducing the rare-ear th element Er into the GaInAs solutions for liquid-phase epitaxy witho ut any complicated processes or an extended bakeout of the growth melt s. The dominant process occurring during the growth of GaInAs layers i n the presence of Er is a very efficient gettering of residual donors. By using Er-doped GaInAs layer as the intrinsic layer in the PIN stru cture, the room temperature front-illuminated PIN photodiodes exhibit good quantum efficiencies of 60% at 1.3 mu m and 83% at 1.6 mu m for d evices with antireflection coatings, which are better than those of 52 % at 1.3 mu m and 65% at 1.6 Irm for the front-illuminated devices wit hout Er doping and comparable to those of 64% at 1.3 mu m and 74% at 1 .6 mu m for commercially available back-illuminated photodiodes. These devices also have a rise time of 88 ps and a pulsewidth of 162 ps for response speed and useful sensitivity to about 3.6 GHz. The detectors respond to pseudorandom modulation at bit rates up to 2.5 Gb/s with a clear eye opening and error free.