Reducing the Cut-In Voltage of a Silicon Carbide/p-Silicon Heterojunction Diode Using Femtosecond Laser Ablation

Abstract

We report on the fabrication of a low-cut-in voltage (a-SiC:H/Si) heterojunction diode using femtosecond laser ablation of silicon wafers in an octane environment. The femtosecond laser-induced plasma simultaneously reduces, carburizes, and hydrogenates the p-type silicon to develop a layer of hydrogenated silicon carbide (a-SiC:H) on top of the p-Si substrate. No reactive gases, source targets, dopants, or diffusion furnaces are required. The obtained current–voltage characteristics of the a-SiC:H/Si diode exhibit a cut-in voltage of 0.16 V, which is significantly lower than the rise potential of a typical SiC Schottky diode (0.75–1.6 eV) or the barrier potential (0.9–1 eV) of a typical p-Si/n-SiC diode. Moreover, this value is far less than the standard cut-in voltage of Si (0.7 V), or the typical body diode SiC MOSFETs (∼3 V). The achieved low cut-in voltage and the modest rectification ratio of the femtosecond laser-fabricated heterojunction diode demonstrate the promising potential of a rapid, facile, and cost-effective method for manufacturing efficient electronic devices.

A Two-Step Femtosecond Laser-Based Deposition of Robust Corrosion-Resistant Molybdenum Oxide Coating

“…This is due to the laser-induced oxygen plasma reacting with the topcoat and oxidizing it. Oxygen diffusion due to thermal and concentration gradients as well as melt hydrodynamic movement are associated phenomena for enhanced oxidation at higher accumulated fluence [70]. The O content in the interior of the MoO x layer may not be the same as that at the exterior surface.…”

“…Usually amorphous/nanocrystalline films are obtained after short laser-matter interaction. The crystallinity has been evidenced to improve with increasing accumulated fluence [70]. This is because higher accumulated fluence induces more reactive oxygen species [71], which not only enhance the MoO x content but also improve the crystallinity of the topcoat [72,73].…”

Enhancing Anticorrosion Resistance of Aluminum Alloys Using Femtosecond Laser-Based Surface Structuring and Coating

“…This might be attributed to the fact that the fast scanning speed for laser nanostructuring does not allow for the proper development of a crystalline structure. Therefore, an amorphous or a short-range nano-crystalline structure was observed [ 65 ]. Rajan et al [ 22 ] reported that fs laser structuring forms alumina with very small intensity peaks, thus depicting partially crystallinity.…”

“…The pulse fluence determines the ablation rate and the penetration depth [ 68 ], where considerable ablation takes place for fluence beyond the ablation threshold [ 30 ]. Similarly, the accumulated fluence determines the morphology and other properties of the surface features that emerge [ 65 ]. Excessive melt hydrodynamic movement and explosive material removal result from ablation at high fluence.…”

Wide-Spectrum Antireflective Properties of Germanium by Femtosecond Laser Raster-Type In Situ Repetitive Direct Writing Technique

“…Compared with other semiconductor materials such as Si and GaAs, Ge has a low coefficient of expansion, high temperature and pressure resistance, chemical stability, and high overload resistance. Ge also has good semiconductor industrial compatibility, as well as good narrow band gap and infrared transmission [3][4][5]. Thus, Ge is widely used in micro-and nano-device fabrication and related industry fields [6,7].…”