THz Nanoscopy of Metal and Gallium Implanted Silicon

TL;DR

This paper employs terahertz near-field microscopy and simulations to investigate the optical properties of Gallium-etched gold patches on silicon, revealing electron transport effects and complex substrate signals, advancing nanoscale THz imaging understanding.

Contribution

It introduces a combined experimental and simulation approach to analyze THz nanoscopy of metal and implanted silicon, highlighting electron transport and signal enhancement phenomena.

Findings

Electron transport influences optical signal strength.

Signal from substrate is complex and not fully understood.

Enhanced signals observed near connected metals with smaller etching areas.

Abstract

Drude model successfully quantifies the optical constants for bulk matter, but it is not suitable for subwavelength objects. In this paper, terahertz near-field optical microscopy and finite element simulation are used to study gold patches fabricated by Gallium etching. Electron transport is discovered in determining the optical signal strength. The signal from substrate is more complicated and still not fully understood. As the etching area decreases, near-field interaction is not dominated by doping concentration, and a higher signal is observed near connected metals. With the help of simulation, the abnormal enhancement phenomenon is discussed in detail, which lays the foundation for further experimental verification.