A microscale nanosecond time-resolved platinum thermometer probing Gaussian pulsed laser induced temperature

TL;DR

This paper presents a high-resolution, nanosecond-scale platinum thin film sensor capable of measuring transient temperature fields induced by pulsed lasers on semiconductor films, with validation through laser melting experiments.

Contribution

It introduces a novel 9ns rise time, 50μm size platinum sensor for high-resolution temperature measurement during pulsed laser processing, including analysis of spatial resolution and accuracy on various substrates.

Findings

Achieved 9ns temporal resolution in temperature sensing.

Validated temperature measurements through laser-induced melting of silicon.

Compared sensing accuracy on different substrates and insulation layers.

Abstract

Pulsed laser processing is playing a crucial role in additive manufacturing and nanomaterial processing. However, probing transient temperature during laser interaction with the processed materials is challenging with both high spatial and temporal resolution. Here, we demonstrate 9ns rise time 50{\mu}m sized Pt thin film sensor for probing the temperature field induced by a nanosecond pulsed laser on a semiconductor thin film. The error sources and associated improvements are discussed regarding the fabrication, sensor pattern and electrical circuits. We further carried out the first experimental and theoretical analysis of spatial resolution and accuracy for measuring gaussian pulse on the serpentine structure. Transparent silica and sapphire substrates, as well as 7-45nm insulation layer thickness, are compared for sensing accuracy and temporal resolution. Lastly, the measured absolute temperature magnitude is validated through the laser-induced melting of the 40nm thick amorphous silicon film. Preliminary study shows its potential application for probing heat conduction among ultrathin films.