Resistive switching devices are part of the next generation of devices being investigated to replace current silicon CMOS technology. These devices are being used as the building blocks for future technologies such as non-volatile memory and data storage, neuromorphic computing and as the basis for next-generation sensing applications. In recent years, amorphous carbon-based resistive switching devices have gained attention through their addition to the International Technology Roadmap for Semiconductors [1]. Carbon-based devices have demonstrated versatility, with various compounds relatively easy to form, and also promise high durability and compelling performance [2].
In this work, we investigate amorphous carbon-based resistive switching devices fabricated using physical vapor deposition techniques. A series of hydrogenated carbon-based resistive layers were deposited using a filtered cathodic vacuum arc with a graphitic carbon source and methane as the H-rich precursor gas. The films were chemically and microstructurally characterised using transmission electron microscopy, electron energy loss spectroscopy, X-ray and ultraviolet photoelectron spectroscopy and elastic recoil detection analysis.
Electrical testing revealed low power, bipolar switching characteristics. Additionally, the devices exhibited inherent resonant tunnelling-based memory that did not require a multilayer structure. Subsequent testing showed that the resonant tunnelling characteristics could be modulated with temperature. Calculation of the band gap revealed the devices had a wide band gap that was shown to increase with increasing methane partial pressure. The devices also exhibited a low work function with the work function decreasing for increasing methane partial pressure.
The well documented tribological properties of hydrogenated amorphous carbon coupled with the characteristics shown in our investigation indicate these devices have use for mechanically durable, low power devices with inherent biocompatibility.