Research On Three Dimensional OEIC Grayscale Lithography Technology

With the rapid development of communication technology, people’s demand for the speed of communication and information capacity is also gradually increased. Due to the slow transmission speed and low bandwidth, electric communication technology can’t meet the demand of the times, and has been replaced by the optical communication network and optoelectronic interconnect technology. Optoelectronic integrated circuit(OEIC) using optoelectronic interconnection technology, based on optoelectronic and microelectronic technology integrates optical devices and electronic devices to convert optical signal and electric signal. It has the advantage of faster speed, greater bandwidth. Optoelectronic interconnect technology has promoted the rapid development of the technology of photonic integrated chip, optical computer, optical interconnection and so on.The main function of OEIC is photoelectric interconnection and the optical path is the optical waveguide structure. At the present stage, the structure of the optical waveguide device is planar optical waveguide, and the three-dimensional structure optical waveguide device has the advantages of small size, high integration degree, and material selection diversity. We start with the device structure, to study how to make the three dimensional optical waveguide device with simple process, low cost and excellent performance.In this paper, we research on the low cost grayscale lithography mask and the three dimensional optical waveguide device. We fabricate grayscale lithography mask by CO2 laser engraver and cutter device fabricating aluminum evaporation mask, and then we using the mask to evaporate the aluminum to the PMMA slice to fabricate grayscale lithography mask. The angle of 3°-6° can be obtained by grayscale lithography, and the angle can be controlled by the thickness of the aluminum film. The lower layer waveguide of the three-dimensional optical waveguide device adopts the ICP etching method to produce the groove, and the lower layer inverted ridge waveguide is fabricated by filling the SU-8 material in the groove. The upper layer waveguide material is divided into photosensitive material and non-photosensitive material, wherein the photosensitive material waveguide is fabricated by waveguide lithography and grayscale lithography. The non-photosensitive material waveguide is duplicated the upper BP-218 structure by the ICP etching method. Complete the process of fabrication, we test the three-dimensional optical waveguide amplifier device. And the test result shows that the optical waveguides are coupled successfully. Finally, the combination of grayscale lithography and nano imprint technology is researched, which makes the fabrication of three-dimensional optical waveguide devices more convenient and efficient.