Amorphous Carbon Films for Electronic Applications

Abstract

While various crystalline carbon allotropes, including graphene, have been actively investigated, amorphous carbon (a‐C) thin films have received relatively little attention. The a‐C is a disordered form of carbon bonding with a broad range of the CC bond length and bond angle. Although accurate structural analysis and theoretical approaches are still insufficient, reproducible structure–property relationships have been accumulated. As the a‐C thin film is now adapted as a hardmask in the semiconductor industry and new properties are reported continuously, expectations are growing that it can be practically used as active materials beyond as a simple sacrificial layer. In this perspective review article, after a brief introduction to the synthesis and properties of the a‐C thin films, their potential practical applications are proposed, including hardmasks, extreme ultraviolet (EUV) pellicles, diffusion barriers, deformable electrodes and interconnects, sensors, active layers, electrodes for energy, micro‐supercapacitors, batteries, nanogenerators, electromagnetic interference (EMI) shielding, and nanomembranes. The article ends with a discussion on the technological challenges in a‐C thin films.

Amorphous carbon material of daily carbon ink: emerging applications in pressure, strain, and humidity sensors

“…Amorphous carbon materials contain different types of orbital configurations (sp, sp 2 , and sp 3 ), which endow them with different physical and chemical properties (such as adjustable conductivity). 6,11 Carbon black, as a typical lowcost amorphous carbon material, is widely used in various sensors (e.g., pressure, strain, humidity, temperature, and biosensors). [12][13][14][15][16][17][18][19][20][21][22][23][24][25] However, the dispersion of pristine carbon black is poor, and it is difficult to be directly used to fabricate sensors; thus, it needs to be compounded with other materials and solutions.…”

“…5 It can be synthesized at low temperature with low cost and is widely used in electronics. [6][7][8][9][10] For the widely used resistive sensors, their basic characteristic is that the conductivity is adjustable; thus, the sensing materials used to fabricate resistive sensors are expected to have appropriate conductivity (i.e., semiconductor State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, P. R. China. E-mail: yuanliu@uestc.edu.cn, taitai1980@uestc.edu.cn…”

“…5 It can be synthesized at low temperature with low cost and is widely used in electronics. 6–10 For the widely used resistive sensors, their basic characteristic is that the conductivity is adjustable; thus, the sensing materials used to fabricate resistive sensors are expected to have appropriate conductivity ( i.e. , semiconductor characteristics).…”

“…Amorphous carbon materials contain different types of orbital configurations (sp, sp 2 , and sp 3 ), which endow them with different physical and chemical properties (such as adjustable conductivity). 6,11 Carbon black, as a typical low-cost amorphous carbon material, is widely used in various sensors ( e.g. , pressure, strain, humidity, temperature, and biosensors).…”

The Amorphous Carbon Thin Films Synthesized by Gas Injection Magnetron Sputtering Technique in Various Gas Atmospheres

“…Thanks to these properties, amorphous carbon layers are of great interest from the application side: tools, photovoltaics, electronics, photonics, biomedical engineering, etc. [4][5][6][7][8][9][10]. The a-C films consist of a mixture of carbon phases with sp 2 and sp 3 hybridization.…”