Mechanism of Electronegativity Heterojunction of Nanometer Amorphous-Boron on Crystalline Silicon: An Overview

Abstract

The discovery of the extremely shallow amorphous boron-crystalline silicon heterojunction occurred during the development of highly sensitive, hard and robust detectors for low-penetration-depth ionizing radiation, such as ultraviolet photons and low-energy electrons (below 1 keV). For many years it was believed that the junction created by the chemical vapor deposition of amorphous boron on n-type crystalline silicon was a shallow p-n junction, although experimental results could not provide evidence for such a conclusion. Only recently, quantum-mechanics based modelling revealed the unique nature and the formation mechanism of this new junction. Here, we review the initiation and the history of understanding the a-B/c-Si interface (henceforth called the “boron-silicon junction”), as well as its importance for the microelectronics industry, followed by the scientific perception of the new junctions. Future developments and possible research directions are also discussed.

Interfacial charge transfer and Schottky barriers at c-Si/a-In heterojunctions

“…Recent ab initio molecular dynamics (AIMD) simulations for the c-Si/a-B interfaces revealed the formation of a distinct border between c-Si and a-B [18][19][20]. Charge transfer occurs from the interfacial Si to the B atoms, which gives rise to the formation of Si +q /B −q barriers.…”