Pulsed Laser Deposition

**3**

**Chapter 1**

**Abstract**

Properties

capacitors are presented.

heterostructure

**1. Introduction**

*Ndioba Niang and Nazir Jaber*

Interface Combinatorial Pulsed

Laser Deposition to Enhance

Heterostructures Functional

*Jérôme Wolfman, Beatrice Negulescu, Antoine Ruyter,* 

In this chapter we will describe a new development of combinatorial pulsed laser deposition (CPLD) which targets the exploration of interface libraries. The idea is to modulate continuously the composition of interfaces on a few atomic layers in order to alter their functional properties. This unique combinatorial synthesis of interfaces is possible due to very specific PLD characteristics. The first one is its well-known ability for complex oxide stoichiometry transfer from the target to the film. The second one is the layer by layer control of thin film growth at the atomic level using in-situ RHEED characterization. The third one relates to the directionality of the ablated plume which allows for selective area deposition on the substrate using a mobile shadow-mask. However PLD also has some limitations and important PLD aspects to be considered for reliable CPLD are reviewed. Multiple examples regarding the control of interface magnetism in magnetic tunnel junctions and energy band and Schottky barrier height tuning in ferroelectric tunable

**Keywords:** combinatorial synthesis, oxide thin films and multilayers, functional

The first report of laser ablation generated plasma to deposit a film dates back to 1965, using a continuous ruby laser [1]. As the obtained film quality was inferior to those made with other deposition techniques at that time, the laser deposition remained confidential for two decades. The discovery mid 80's of the high Tc superconductor YBa2Cu3O7-x (YBCO) [2–3] triggered a frantic search for room temperature superconducting cuprates materials, including strong effort for thin film synthesis. The complex cuprate cationic composition makes film growth difficult using conventional physical vapor deposition (PVD) techniques like magnetron sputtering or evaporation. Indeed, to grow films with the right com-

sputtering

position it is mandatory to start with a stoichiometric plasma. The Ar+

rate of multi-cationic targets and the distribution in the plasma strongly depends on the cations mass, which precludes the use of a stoichiometric target to obtain
