Research On ICP Etching Process Of GaAs-based VCSEL Devices

As a representative of the second generation semiconductors,gallium arsenide?GaAs?-based materials have the advantages of high electron mobility,high energy conversion efficiency,and small dielectric constant.They have irreplaceable advantages as materials for making optoelectronic devices.As a new type of laser,vertical cavity surface emitting lasers?VCSELs?are mostly made of gallium arsenide-based materials.They have the advantages of low threshold current,good beam directivity,and high integration.They are used in 3D imaging,unmanned driving,the Internet of Things,and data communication.It is widely used in other fields.Etching process plays a key role in the process of preparing vertical cavity surface emitting lasers from GaAs-based materials,and plays a key role in subsequent processes and even device performance.Therefore,the etching process of GaAs-based vertical cavity surface emitting lasers has been studied.,Has great significance for the preparation of VCSEL devices.In this paper,the ICP etching process of GaAs-based VCSEL devices is experimentally studied.The NE-950 EXz etching machine of ULVAC company was used to etch GaAs-based materials,and the JSM-7500 F scanning electron microscope of Japan Electronics Company was used to characterize the micro-morphology of the etching pattern.The effects of different equipment parameters and process gases on the etch rate and pattern morphology of GaAs-based materials were studied.The experimental results show that the increase of ICP source power,RF bias power,cavity pressure and Cl₂ gas flow will increase the etching rate on the one hand,but the mechanism that affects the rate will be different,and on the other hand,it will have a certain effect on the pattern morphology However,the increase of BCl₃ and Ar gas flow will reduce the etching rate.Among them,the change of BCl₃ gas flow has a greater impact on the pattern morphology.In the course of the experiment,we found that by-products were adsorbed on the surface of the material.Through the study of its production mechanism and surface morphology optimization experiments,the ideal etched surface morphology with no products and an etching uniformity of 2.6% was finally obtained.Through the research in this paper,a suitable etching rate,smooth sidewalls,and flat topography patterns were obtained.This has accumulated relevant experience for the ICP etching process of GaAs-based VCSEL devices and has certain reference value.