An improved continuous compositional-spread technique based on pulsed-laser deposition and applicable to large substrate areas

TL;DR

This paper introduces an improved continuous compositional-spread technique using pulsed-laser deposition, enabling large-area thin films with uniform composition for advanced material analysis.

Contribution

The novel method overcomes previous limitations by providing uniform thickness and energetics across large substrates during compositional spreading.

Findings

Successful fabrication of large-area (Sr,Ca)RuO₃ compositional spreads.

Enhanced uniformity in film thickness and composition.

Potential for detailed property analysis across the spread.

Abstract

A new method for continuous compositional-spread (CCS) thin-film fabrication based on pulsed-laser deposition (PLD) is introduced. This approach is based on a translation of the substrate heater and the synchronized firing of the excimer laser, with the deposition occurring through a slit-shaped aperture. Alloying is achieved during film growth (possible at elevated temperature) by the repeated sequential deposition of sub-monolayer amounts. Our approach overcomes serious shortcomings in previous in-situ implementations of CCS based on sputtering or PLD, in particular the variations of thickness across the compositional spread and the differing deposition energetics as function of position. While moving-shutter techniques are appropriate for PLD-approaches yielding complete spreads on small substrates (i.e. small as compared to distances over which the deposition parameters in PLD vary, typically about 1 cm), our method can be used to fabricate samples that are large enough for individual compositions to be analyzed by conventional techniques, including temperature-dependent measurements of resistivity and dielectric and magnetic and properties (i.e. SQUID magnetometry). Initial results are shown for spreads of (Sr,Ca)RuO$_3$.