An in-situ thermoelectric measurement apparatus inside a thermal-evaporator

TL;DR

This paper presents an innovative in-situ measurement apparatus for thermoelectric properties during thin film deposition inside a thermal evaporator, enabling real-time characterization at high temperatures and reducing uncertainties associated with ex-situ methods.

Contribution

The authors designed and calibrated a novel in-situ thermoelectric measurement system integrated within a thermal evaporator for real-time analysis of ultra-thin films.

Findings

Successfully measured thermoelectricity of Bi, Te, and Bi₂Te₃ at temperatures up to 500 K.

Demonstrated the system's capability to generate and measure temperature differences during deposition.

Reduced uncertainties in thermoelectric characterization of ultra-thin films.

Abstract

At the ultra-thin limit below 20 nm, a film's electrical conductivity, thermal conductivity, or thermoelectricity depends heavily on its thickness. In most studies, each sample is fabricated one at a time, potentially leading to considerable uncertainty in later characterizations. We design and build an in-situ apparatus to measure thermoelectricity during their deposition inside a thermal evaporator. A temperature difference of up to 2 K is generated by a current passing through an on-chip resistor patterned using photolithography. The Seebeck voltage is measured on a Hall bar structure of a film deposited through a shadow mask. The measurement system is calibrated carefully before loading into the thermal evaporator. This in-situ thermoelectricity measurement system has been thoroughly tested on various materials, including Bi, Te, and Bi$_2$Te$_3$, at high temperatures up to 500 K.