Monolithic integration of SEEDs and VLSI GaAs circuits by epitaxy on electronics

Using the epitaxy-on-electronics (EoE) process, self-electrooptic effect devices (SEEDs) have been monolithically integrated with VLSI GaAs electronics. The EoE approach provides both depletion-mode and enhancement-mode MESFETs for large-scale, high-density optoelectronic circuits. The performance of SEEDs grown by molecular beam epitaxy at a reduced temperature compatible with the EoE process is shown to be robust, and modulators with contrast ratios of 2.3:1 at 7.5-V bias have been integrated on commercially processed VLSI GaAs circuits. The EoE-SEED process offers potential improvements over the FET-SEED process, facilitating the applications of SEEDs in free-space optical switching and computing.