Pulsed Laser Template Engineering- PLATEN

TL;DR

PLATEN is a novel laser-based patterning method that enables high aspect ratio patterning of difficult-to-etch oxide films by replicating silicon substrate topography with high precision, even at nanoscale features.

Contribution

The paper introduces PLATEN, a new laser-based patterning technique that allows high-resolution patterning of oxide films on silicon substrates with complex topographies.

Findings

Effective pattern replication down to 50 nm features.

Oxide films replicate silicon topography with 80 nm thickness.

Demonstrated near single crystalline oxide growth on patterned substrates.

Abstract

Thin films of functional inorganic materials, particularly oxides, play a vital role in optoelectronics, enabling applications that range from active optical components to MEMS-based architectures. Achieving high aspect ratio patterning of these functional materials remains a significant challenge, as many of their constituent elements do not readily form volatile compounds required for conventional reactive ion etch processes. We introduce a novel approach, Pulsed Laser Template ENgineering (PLATEN), which offers a more accessible route for patterning materials that are typically difficult to etch. This technique involves depositing functional films using the Pulsed Laser Deposition (PLD) process onto silicon substrates that have been pre-patterned using reactive ion etching to create high aspect ratio features. Due to the highly forward-directed nature of the PLD process, the deposited films replicate closely the topography of the patterned silicon, without coatings the sidewalls. This process remains effective even at feature sizes down to approximately 50 nm. The oxide films replicate the underlying silicon pattern to a thickness of 80 nm. For thickness beyond 80 nm the patterns develop a waist at the midpoint which scales with film thickness and is not dependent on the feature size. In this paper, we present a detailed analysis of the PLATEN process, including deviations from ideal pattern replication in sub-micron features as a function of film thickness, and demonstrate near single crystalline growth of oxides on the patterned silicon substrate, demonstrating the potential of PLATEN technique for active opto-electronic materials.