LiNbO3waveguide modulator with 1.2 µm thick electrodes fabricated by lift-off technique

In order to make efficient high-frequency electrooptic modulators, the microwave loss in the electrodes has to be minimized. A lift-off technique using chlorobenzene to harden the top of AZ1350-J photoresist was adopted to fabricate 1.2 μm thick metal electrodes. A 1 cm long, 15 μm wide strip electrode has a dc resistance of 11 Ω, which is substantially less than that of the 2000 Å thick electrodes routinely fabricated. A 1 cm long traveling-wave phase modulator consisting of a single waveguide was tested. The measured -3 dB bandwidth is 3.8 GHz.