Shanghai Microsystems has made progress in the preparation of layer-controlled graphene films

Recently, the SOI Materials Research Group of the State Key Laboratory of Functional Materials for Materials of the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences has made new progress in the preparation of layer-controllable graphene films. The research group designed the Ni/Cu system and introduced the carbon source using ion implantation technology. By precisely controlling the dose of injected carbon, the layer of graphene was successfully controlled. Relevant research results were published as the Back Cover article in Advanced Functional Materials 2015 issue 24 with the Synthesis of Layer-Tunable Graphene: A Combined Kinetic Implantation and Thermal Ejection Approach.

Graphene is widely recognized as the most competitive electronic material that continues Moore's Law in the post-silicon CMOS era because of its excellent electrical properties, excellent thermal conductivity, and excellent mechanical properties, and has broad application prospects. However, the number of graphene layers must be precisely controlled for specific application requirements.

The SOI materials group of Shanghai Institute of Microsystems has focused on graphene layer number control issues, combined the characteristics of Ni and Cu to prepare graphene in the CVD process, and designed the Ni/Cu system using two materials that have different carbon dissolution capabilities. A 300 nm Ni layer is electron beam evaporated on a 25 μm thick Cu foil, and carbon ions are implanted into the Ni layer in the Ni/Cu system using mature ion implantation techniques in the semiconductor industry by controlling the dose of carbon ions implanted. (ie 4E15 atoms/cm2 dose corresponds to monolayer graphene, 8E15 atoms/cm2 dose corresponds to double-layer graphene), and single-layer and double-layer graphene were successfully prepared after annealing.

Compared with conventional CVD process for preparing graphene, ion implantation technology has the advantages of low temperature doping, precise energy and dose control, and high uniformity. The number of graphene single and double layers prepared by ion implantation is only affected by the carbon injection dose. , regardless of the volume ratio of gas, substrate thickness, and growth temperature. In addition, ion implantation technology is compatible with modern semiconductor technology, which helps to realize the real application of graphene as an electronic material in the field of semiconductor devices.

The study was supported by relevant research projects such as the National Natural Science Foundation of China's Innovation Research Group, the Excellent Youth Fund, and the High-mobility Materials Innovation Research Team of the Chinese Academy of Sciences.