Raman characterization method of corrosion stress of alpha surface GaN epitaxial layer film

Abstract

The invention discloses a Raman characterization method of corrosion stress of an alpha surface GaN epitaxial layer film. The Raman characterization method comprises the following steps of 1, cleaning the surface of an alpha surface GaN epitaxial layer film, 2, carrying out a Raman scattering test on the alpha surface GaN epitaxial layer film to obtain a frequency shift value of an uncorroded E2 phonon mode, 3, carrying out a KOH solution corrosion test and decontamination treatment on the alpha surface GaN epitaxial layer film, and carrying out a Raman scattering test on the corroded alpha surface GaN epitaxial layer film to obtain a frequency shift value of a corroded E2 phonon mode, and 4, according to an offset delta E2 which is the difference of the frequency shift value of the corroded E2 phonon mode of the alpha surface GaN epitaxial layer film and the frequency shift value of the uncorroded E2 phonon mode of the alpha surface GaN epitaxial layer film, calculating corrosion stress of the alpha surface GaN epitaxial layer film by a formula of sigma xx=delta E2 / k, wherein k is a constant. Through adopting two Raman scattering tests on an alpha surface GaN epitaxial layer filmbefore and after the corrosion, the Raman characterization method eliminates the influence from a substrate on alpha surface GaN epitaxial layer film stress, wherein when a conventional Raman characterization method is adopted, the influence exists. Through the Raman characterization method, calculated corrosion stress of an alpha surface GaN epitaxial layer film has a small error. Therefore, theRaman characterization method can be utilized for characterization of corrosion stress of alpha surface GaN epitaxial layer films having different structures.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and relates to a corrosion and characterization method of semiconductor materials, in particular to a Raman characterization method of film corrosion stress. Background technique [0002] The microfabrication technology based on silicon material marked by integrated circuit has created the contemporary information society. It is generally believed that the processing limit of silicon materials is 10nm line width. Restricted by physical principles, it is impossible to produce high-frequency, high-speed and high-power optoelectronic devices with stable performance and higher integration if the thickness is less than 10nm. Therefore, the current technological progress on silicon materials will become more and more difficult, and people place their hopes on the electronic behavior of the third-generation semiconductor materials, namely III-V nitrides and their alloy materials. The first th...

AI Technical Summary

Problems solved by technology

At present, there are many methods for measuring film stress, mainly including Raman method, X-ray diffraction method, twin crystal diffraction method and laser interferometry. The lattice parameters are compared to calculate the strain parameters of the epitaxial film, and then according to the elastic strain theory, the stress condition of the epitaxial film is obtained. The method is relatively complicated, and the resulting error is also large; The method, because it only uses the shift of the Raman phonon peak for a single time, cannot eliminate the shift of the phonon peak induced by the substrate material, resulting in a large error in the stress of the epitaxial layer film

Images