Abstract
In the rapidly digitalized world, information systems are expected to become faster, cheaper, and more reliable. The traditional semiconductor industry has been miniaturizing silicon-based transistor technology for a long time to meet higher performance targets. As current technology approaches its miniaturization limits, the research community is exploring to replace silicon with two-dimensional (2D) materials to achieve long-term sustainable performance gains and support this digital growth. Combined with the emerging industry of flexible electronics, is driving the industry towards assessing materials with additional non-conventional properties like high flexibility for wearable devices. One such candidate material for 2D insulators is 2D muscovite mica (2D mica). Its wide-bandgap electronic structure, high dielectric constant, thermal stability, chemical resistance, and high flexibility make it a potential candidate for future 2D insulators in various FETs. However, its electrical reliability for its use as a 2D insulator is yet to be studied.
This work presents the first comprehensive experimental study into the dielectric breakdown properties of 2D mica. The research involves the fabrication and characterization of 2D mica flakes and nano-capacitors, followed by an analysis of their breakdown (BD) performance characteristics. Key stressing techniques include Ramped Voltage Stressing (RVS), and Constant Voltage Stressing (CVS) which reveal mica’s high dielectric breakdown field strength, low leakage current, and strong electrical reliability compared to other 2D insulators. The BD behavior is found to be uniquely different than other 2D dielectrics h-BN and SiO₂, in that BD occurs at very low current levels, the BD event is abrupt, and catastrophic destructive BD readily occurs. An extended analysis based on experimental results leads to a hypothesis that potassium ions intercalated within mica layers play a role in the electrical breakdown mechanism. The study highlights the low leakage current, and unique breakdown behavior of mica, positioning it as a promising material for low-power memory devices and flexible electronics.