CMOS-Compatible PECVD Silicon Carbide Platform for Linear and Nonlinear Optics

Silicon carbide (SiC) is considered a promising platform for linear and nonlinear photonics due to its large band gap, large refractive index, low thermo-optic coefficient, large Kerr nonlinearity, and good mechanical stability. We evaluate amorphous SiC (a-SiC) deposited on an insulator, using plasma-enhanced chemical vapor deposition, as a nonlinear optical material. Deposited films possess a band gap of 2.3 eV and refractive index of 2.45 at a wavelength of 1550 nm. Ring resonators with intrinsic quality factor as high as 1.6 x 10(5) are demonstrated. Waveguides with loss as low as 3 dB/cm enable low loss linear integrated photonics. The Kerr nonlinearity of a-SiC around 1550 nm is measured to be 4.8 x 10(-14) cm(2)/W-1 order of magnitude higher than previous results measured for both crystalline and amorphous SiC. Nonlinear loss characterization shows that two-photon absorption is absent. The three-photon absorption coefficient is characterized to be similar to 0.01 cm(3)/GW(2). The strong Kerr nonlinearity makes a-SiC a great platform for CMOS-compatible nonlinear photonics.