Room-temperature formation of Pt$_3$Si/Pt$_2$Si films on poly-Si substrates

TL;DR

This study demonstrates a novel room-temperature method to create bilayer Pt$_3$Si/Pt$_2$Si films on poly-Si substrates using sputtering and etching, with detailed structural and compositional analysis confirming the formation process.

Contribution

It introduces a new room-temperature fabrication process for bilayer silicide films on poly-Si, verified by spectroscopic analysis and structural characterization.

Findings

Successful formation of Pt$_3$Si/Pt$_2$Si bilayers at room temperature

Verification of Pt$_2$Si formation via X-ray photoelectron spectroscopy

Identification of the formation mechanism involving sputtering and wet etching

Abstract

We propose a way of formation of thin bilayer Pt$_3$Si/Pt$_2$Si films at room temperature on poly-Si substrates by Pt magnetron sputtering and wet etching, obtain such film, investigate its structure and phase composition and estimate the thickness of its layers. We verify by direct x-ray photoelectron-spectroscopic measurements our previous observation of the Pt$_2$Si layer formaton between Pt and poly-Si films as a result of Pt magnetron sputtering at room temperature. This layer likely appears due to high enough temperature of Pt ions in the magnetron plasma sufficient for chemical reaction of the silicide film formation on the Si surface. The Pt$_3$Si layer likely forms from the Pt--Pt$_3$Si layer (Pt$_{95}$Si$_5$), which arises under Pt film during the magnetron sputtering, as a result of Pt removal by wet etching.