Fabrication of Crystalline Si Waveguides on (1 0 0) Bulk Si Substrate Using Laser Reformation Method

Optical solution has been proposed for short-reach interconnects. A primary concern is the integration of photonics and electronics. A method to fabricate crystalline Si waveguides on insulator from bulk Si substrate using a laser reformation technique is here presented. A high-power laser is used to melt and reshape a Si fin structure. This is followed by an oxidation process to produce oxide as an optical isolation layer beneath the Si and form the waveguide structure. The Si waveguide, using laser reformation method in our experiment, has 140 nm width and 420 nm height, showing a single mode property and an effective refractive index of about 2.09. It represents a viable method for creating crystalline Si waveguides on CMOS-compatible Si substrate and reveals the potential of Si photonic devices integrated with Si electronics.