Electronic Materials

• Thin Film Epitaxy
• Pulsed Laser Deposition
• High Temperature Superconductors

The Electronic Materials & Devices (EMD) Group at AFR conducts research and development of advanced thin film materials for electronic device applications as well as development of in-situ thin film metrology tools.  For over a decade, research at AFR has involved epitaxial growth of high temperature superconductor (e.g., YBa2Cu3O7-x), ferroelectric (e.g., Pb(Zr,Ti)O3, (Ba,Sr)TiO3), dielectric (e.g., YSZ, CeO2, CaF2) and semiconductor (SiC) thin films on various substrate materials including silicon wafers.

The primary deposition technique at AFR is pulsed laser deposition (PLD).  In PLD, an intense pulsed laser beam (typically ultraviolet) is focused onto a target resulting in a highly energetic plasma, the so-called plume, of neutrals and ions which are directed onto a heated substrate.  The pulsed energy density at the target is the driving force for effectively depositing materials containing elements with different vapor pressures.  Using the correct process parameters (e.g., appropriate energy density range), PLD has an inherent ability to maintain the target stoichiometry in the deposited film.  By virtue of its versatility and relative simplicity, PLD is a convenient method for depositing multi-layer structures, in-situ, utilizing a movable, multi-target holder.  Although PLD has not emerged as a mainstream technique for commercial thin film deposition, it is widely regarded as an excellent research tool for rapidly exploring thin film materials and structures. 

Two PLD chambers are available at AFR for deposition of a wide variety of materials.  The first is a turbomolecular-pumped system configured for PLD of up to five materials in-situ in a single deposition routine.  The second is a hybrid system for deposition of thin film materials by PLD and/or thermal evaporation.