A method and device for detecting sidewall roughness of an SOI optical waveguide

Abstract

The invention relates to a side wall roughness detecting method and device for an SOI optical waveguide. The technology and equipment are simple. By the adoption of the method and device, a low side wall can be measured. According to the technical scheme, a groove type insulating cover which is open downwards is manufactured with an insulating material and covers the optical waveguide through the bonding technology, and then a closed micro-channel with two ends open is formed between the side wall, to be detected, of the optical waveguide and the groove type insulating cover and a silicon dioxide buried layer; ionic liquid or polar liquid is introduced into the micro-channel so that the liquid can flow along the whole side wall, to be detected, of the optical waveguide in the micro-channel; the potential difference between the two ends of the optical waveguide is measured, and the roughness of the side wall, to be detected, of the optical waveguide is obtained according to the non-linear relationship between the potential difference between the two ends of the silicon optical waveguide when the liquid flows through the side wall of the silicon optical waveguide and the roughness of the side wall of the silicon optical waveguide. The method and device are suitable for measurement of MEMS devices.

Description

technical field [0001] The invention belongs to the sidewall roughness measurement technology of micro-nano devices, and in particular relates to a sidewall roughness detection method and device for SOI optical waveguides. Background technique [0002] For the roughness measurement of the sidewall of micro-nano devices, the existing technologies at home and abroad include: observing the device structure through an electron microscope and using electron microscope photos to estimate the roughness, or scanning and imaging through an atomic force microscope. [0003] Although the estimation method based on the electron microscope is simple, the measurement is not accurate enough; although the ordinary atomic force microscope can magnify the test area thousands of times, the calculation of the sidewall roughness can only be measured by destroying the structure of the device; especially for Due to the low micro-nano structure sidewall, the movement and force of the probe are affe...

AI Technical Summary

Problems solved by technology

[0003] Although the estimation method based on the electron microscope is simple, the measurement is not accurate enough; although the ordinary atomic force microscope can magnify the test area thousands of times, the calculation of the sidewall roughness can only be measured by destroying the structure of the device; especially for Low micro-nano structure sidewall, the movement and force of the probe are affected by the bottom surface, which cannot achieve accurate and fast imaging

[0004] Aiming at these problems, there are some solutions, among which: the patent (201410310642.1) introduces a test method based on atomic force microscope. The rotation angle of the needle can realize the surface characterization of the large-angle sidewall of the micro-nano structure without destroying the sample; the patent (201410364545.0) proposes a method of detecting the etched sidewall by capacitance change, although this method does not require Destroy the sample structure, but need to add additional process flow before the functional area fabrication process

[0005] Therefore, the above-mentioned technology is modified on the original instrument or process, not only the process and equipment are more complicated, but also the roughness measurement of the low side wall is still impossible

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