Silicon-based long-wave infrared waveguide and preparation method thereof

Abstract

The invention discloses a silicon-based long-wave infrared waveguide and a preparation method thereof. The preparation method comprises the following steps of: preparing a waveguide structure on a common silicon slice, preparing a silicon dioxide mask by using a thermal oxidation method, and then carrying secondary photoetching; setting windows on both sides of a waveguide, carrying out wet corrosion by using a KOH (Potassium Hydroxide) solution, and realizing etching speeds of different crystal faces by selecting a proper concentration and a temperature; and achieving the purpose of slotting by using side corrosion. The long-wave infrared waveguide prepared in the method has simple structure and low process difficulty and is prepared from the common silicon slice without an expensive SOI slice and realizes back deep etching without stopping a corrosion process. For different wavelengths, low transmission loss can be realized by optimizing structural parameters.

Description

technical field [0001] The invention relates to an integrated optical device, in particular to a silicon-based long-wave infrared (above 3um) optical waveguide structure prepared by a trapezoidal platform supporting an inverted trapezoidal lower end surface based on a wet etching process and a preparation method thereof. Background technique [0002] Since the new century, the IT industry represented by the Internet and the new generation of mobile communication technology has greatly promoted the research and development of integrated optoelectronic devices, and its own development has also promoted their application scope, gradually expanding from the communication field to the industrial , military, energy, medical, biological, sensing and other fields. In particular, silicon-based optoelectronic devices combined with the current mature CMOS technology create the possibility of low-cost, large-scale functionalization and modularization. [0003] At present, the silicon-b...

AI Technical Summary

Problems solved by technology

This structure is more difficult for the process requirements, and cladding layers of different materials need to be deposited repeatedly; compared with the present invention, the Undercut SOI waveguide structure requires a self-stop process for deep etching, and also requires secondary oxidation on the substrate silicon and secondary lithography, and there is an alignment problem

In addition, due to the need to etch the entire silicon substrate of more than 350um, the thickness of the silicon dioxide layer used as a mask is greatly increased, and the required thickness cannot be achieved only by thermal oxidation, and sputtering and other methods are also required; The freestanding structure waveguide prepared by the beam direct writing method has too high requirements on the equipment, and it is difficult to prepare a larger size, and the loss is relatively large in the application of long-wave infrared

Images