Study Of ECR Plasma Anisotropic Etching Of Single Layer Graphene

Since its successful preparation in the laboratory,graphene has become the frontier of science and technology and the focus of research in the world with its special linear band structure and excellent electrical,thermal,optical and mechanical properties.It is also considered as a revolutionary material for future integrated circuits in order to realize the transition from process to"Ai"in the order of magnitude.Graphene has many amazing possibilities in new physical applications and new electrical applications,but many applications can only be achieved by defining graphene as nanoribbons or other nanostructures.Controllable and mass production methods have great potential for the manufacture of graphene based devices.We must find a reliable way to generate graphene nanostructures with specific size,geometry and orientation under controlled conditions.Graphene is often patterned in semiconductor applications.As graphene is an ultra-thin two-dimensional nanomaterial,etching graphene is the best way.Dry plasma etching technology is the basic process of pattern transfer in the field of microelectronics.It is also a common process of graphene etching.It can realize anisotropic etching of graphene and obtain edge orientation of specific structure.In the plasma etching process of graphene,capacitive coupled plasma?CCP?and inductively coupled plasma?ICP?are the most commonly used plasma sources.For etching graphene using electron cyclotron resonance?ECR?plasma with higher energy density,there is no relevant research,and there are still existing.In the research of plasma etching graphene,the etching gas used is relatively single,which is not conducive to the application in many environments.In addition,compared with the lower layer graphene,the single layer graphene is more etched.In this study,we used microwave ECR plasma to etch monolayer graphene,and studied the effects of H₂,N₂,O₂ and AR and their mixture on etching rate,anisotropy,surface and substrate smoothness of monolayer graphene,in order to obtain more accurate etching with higher degree of anisotropy.Following is the main conclusions of this study:?1?Microwave ECR plasma is favorable for etching single layer graphene.Usually,in plasma etching,single layer graphene is easier to etch than few layer graphene,and microwave ECR plasma energy is less than 30eV,so the damage to the sample is less.By adjusting the radio frequency power and the height of the substrate,controlling the plasma energy can better control the etching site of graphene and make the stone.The etching of melene occurs only where we need it,but there are few new etchings in other locations.Meanwhile,due to the low energy of microwave ECR plasma,the sputtering etching of SiO 2 on the substrate will be much reduced,which is conducive to ensuring the smoothness of the substrate.?2?H₂ plasma is anisotropic etching of graphene.By adjusting discharge parameters,the etching rate of graphene by H₂ plasma can be adjusted in a wide range,which is very suitable for graphene patterning and meets various environmental and etching requirements.?3?Under conventional microwave ECR plasma,N₂ plasma does not etch graphene basically.This shows that N₂ can be used as a good auxiliary etching gas to change the plasma environment of discharge gas in order to better control the etching rate.At the same time,in the discharge process,N₂ plasma has no damage to graphene,which is conducive to the smooth graphene.?4?In the microwave ECR plasma environment,the etching rate of graphene by O2 plasma is very high,and there are many etching sites,which is not conducive to the controllable etching of graphene,but the damage to SiO 2 substrate is small.The rate of graphene etching can be controlled by mixing a certain proportion of Ar gas in O₂,but the etching hole is circular and isotropic.?5?H₂/N₂ and H₂/Ar mixed gases are suitable for controlled etching of graphene and have little damage to SiO 2.