Research On Electron Beam Induced Direct Writing Metallic Nanowires In SEM

To develop nanotechnology and seize development opportunities is not only an important means for China to enhance the core competitiveness of the country's high-end manufacturing industries,but also a necessary way to promote China's industrial transformation and upgrading and to become a manufacturing powerhouse.Nano-manufacturing technology occupies an important position in nanotechnology and has attracted widespread attention and rapid development in recent years.However,there is no effective nano-interconnect processing technology in the field of nano-manufacturing.It's significant for nano-interconnect technology to develop nano-integrated circuits and improve nano-electronic devices.Electron beam processing technology is a simple,high-efficiency,precise nanofabrication method,based on scanning electron microscopy(SEM).As a new application technology of electron beam at nanometer scale,electron beam induced metal nanowire direct writing technology has the characteristics of high accuracy,direct writing,and good controllability.As a new application technology of electron beam at nanometer scale,the technology of electron beam induced metallic nanowire direct writing has the characteristics of high accuracy,direct writing,and good controllability.It is able to achieve a variety of metallic nanowires direct writing,and achieve direct patterning write.It provides a new solution for manufacturing high-precision and high-performance nanoelectronic devices and nanoscale integrated circuits,and has a very broad application prospect in the field of nano-integrated circuits and nano-interconnections.This paper proposes a technique of direct writing metallic nanowires using electron beam induced direct writing.On this basis,the automated nanowire technology of electron beam induced metal nanowires was realized by software.The main contents of this paper are listed as follows:(1)The energy mechanism of electron beam melting nanoparticle was studied,and the model of electron beam thermal field distribution was established.The interaction during the electron beam writing process was analyzed,which laid a solid theoretical foundation for this paper.Firstly,,the process of electron beam energy transferred to metal nanoparticle was analyzed,based on the working principle of the scanning electron microscope.Secondly,the thermal field distribution of electron beam was mathematically interpreted,and the mathematical model of the thermal field distribution is established,based on the statistical interpretation of the wave function and the central limit theorem.When the experimental conditions were as follows: accelerating voltage U=20k V,electron beam current I=49.5?A,working distance WD=4.3mm(Inlens mode),the theoretical value of electron beam energy density on the surface of metal nanoparticles was qs=3.7×105 w/?m2.The effective energy density of electron beam induced metal nanowire writing was achieved.Finally,electrostatic force between the electron beam and metallic nanoparticles,the adhesion between metallic nanowires and the substrate,and the surface tension of metal nanowires were analyzed and the mechanics of them were established,during the direct writing process of electron beam induced metal nanowires.(2)Based on the principle of ultrasonic dispersion,the process parameters of dispersed metallic nanoparticles were studied and experimentally demonstrated.The experimental parameters of ultrasonic dispersion were optimized,the agglomeration of metallic nanoparticles was reduced,and the dispersion results of metal nanoparticles were better.It provided raw materials for electron beam induced metallic nanowires direct writing.(3)Six kinds of nanowires,such as Ag,Cu,Au,Al,Pt,and Pd,were directly written at different electron beam induction times,and 10 sets of repeated direct writing experiments were performed.The statistical results of the experiment showed that in the period of 1 to 5 minutes,Ag nanowires have a length of 121 nm to 1136 nm,Cu nanowires have a length of 67 nm to 1025 nm,Au nanowires have a length of 93 nm to 902 nm,Al nanowires have a length of 153 nm to 1328 nm,and Pt nanometers.The length of the line is 57 nm to 1140 nm,and the length of the Pd nanowire is 137 nm to 859 nm.By analyzing the relationship between the electron beam induction time and the length of the metal nanowires,the electron beam inducded time was positively correlated with the length of the same metallic nanowires.On the basis of realizing the direct writing of metal nanowires,a simple patterned Au nanowire direct writing experiment was further performed,and an "L" type Au nanowire with a total length of 1459 nm and a "mouth" type Au nanowire with a total length of 1880 nm were directly written.Finally,the three-dimensional topography of the short-line type,long-line type,"L" type,and " " type Ag nanowires was measured by an atomic force microscope.The experimental results showed that,the electron beam direct writing Ag nanowires had good homogeneity,under the same experimental conditions.(4)Electron beam induced direct writing linear and arc-shaped Ag nanowires were automatically realized by software.And the influence of nano-operation platform vibration and scanning electron microscope imaging drift on the electron beam motion path was weakened by interpolation algorithm of point-by-point comparison,the error between nanowires and the predetermined trajectory was reduced,and the results of automated direct writing were optimized.Direct writing of Ag nanowires in any direction from 0° to 360° in the plane and of Ag nanometer arcs with a radius of 207 nm were available.