The Process and Mechanism of Preparing Nanoporous Silicon: Helium Ion Implantation

Abstract

Ion implantation is an effective way to control performance in semiconductor technology. In this paper, the fabrication of 1~5 nm porous silicon by helium ion implantation was systemically studied, and the growth mechanism and regulation mechanism of helium bubbles in monocrystalline silicon at low temperatures were revealed. In this work, 100 keV He ions (1~7.5 × 1016 ions/cm2) were implanted into monocrystalline silicon at 115 °C~220 °C. There were three distinct stages in the growth of helium bubbles, showing different mechanisms of helium bubble formation. The minimum average diameter of a helium bubble is approximately 2.3 nm, and the maximum number density of the helium bubble is 4.2 × 1023 m−3 at 175 °C. The porous structure may not be obtained at injection temperatures below 115 °C or injection doses below 2.5 × 1016 ions/cm2. In the process, both the ion implantation temperature and ion implantation dose affect the growth of helium bubbles in monocrystalline silicon. Our findings suggest an effective approach to the fabrication of 1~5 nm nanoporous silicon, challenging the classic view of the relationship between process temperature or dose and pore size of porous silicon, and some new theories are summarized.

Drug release control and anti-inflammatory effect of biodegradable polymer surface modified by gas phase chemical functional reaction

“…For effective drug delivery, the introduction of mediators such as drug carriers and hydrogels or physical methods such as creating micropores on a material surface have been investigated [5][6][7][8]. In particular, to store and deliver drugs, it has been reported that micropores can be formed on the material surface using laser-based physical surface modification methods such as ion beam and femtosecond laser irradiation or chemical surface modification methods such as anodic oxidation and polishing [9][10][11][12]. However, physical methods such as laser irradiation have limitations such as variations in the irradiation conditions for each material property, slow processing speed, and high cost.…”

Investigation of the Optical Nonlinearity for Au Plasmonic Nanoparticles Based on Ion Implantation

“…Compared to the methods mentioned above, the ion implantation process [15,16] is a relatively mature technology for synthesizing NPs with abundant advantages such as the uniformity of produced NPs. The ion implantation method can achieve large-scale material modification through simple operations, forming new doping systems and obtaining excellent device performance.…”