Solmates-PLD plasma plume

Pulsed Laser Deposition explained

Pulsed laser deposition (PLD) is a physical vapor deposition method that uses high energetic laser light to energize material, creating a deposition vapor that can be condensed on any possible substrate.

PLD is recognized as a very versatile thin film deposition technology, popular in academics and R&D Institutes. Particularly complex multi-compound materials where supersaturation promotes easy nucleation/crystallization at relatively low surface temperatures. In a high pace industry eager for novel ‘material systems’, Solmates aims to complement conventional technologies like ALD and reactive sputtering.

How pulsed laser deposition is done

A pulsating UV-laser bundle is focused onto a deposition target which is positioned inside a vacuum chamber, leading to a very high local energy density on the surface of this deposition target. When this energy density exceeds a materials ablation threshold, the absorbed energy leads to expansion of the material perpendicular to the deposition targets surface, creating a plasma.

Whats pulsed laser deposition looks like

In a typical PLD process, the energy focused on a deposition target’s surface is significantly above the ablation threshold, giving the deposition species even more kinetic energy as they expand into the vacuum chamber.

Benefits of Pulsed Laser Deposition

Competitive edge when it comes to material nucleation at the substrate interface

The expanding plasma plume, consisting of excited atoms, small and large clusters, is condensed onto a wafers interface by placing the substrate in direct line of sight with the plasma. The high density and energy of the species inside the deposition plasma leads to the

formation of metastable material phases that are associated with supersaturated film growth. This gives PLD an competing edge when it comes to material nucleation at the substrate interface. This leads to high crystallinity film growth at lower deposition temperatures, starting right from the first few nanometers. As PLD does not require any bias applied to the substrate or target, the technology is a very suitable deposition method for thin film growth onto different conducting and non-conducting substrates.

Further control over the deposition process occurs by influencing the plasma species as they travel towards the substrate. The use of reactive and inert gasses inside the vacuum chamber creates an opportunity to tune the deposition kinetics as well as the film stoichiometry, which influences the growth mechanism of the deposited thin film. It is this extensive freedom to control the growth kinetics during the PLD process that drive most of the powerful and unique advantages in PLD thin film processing, creating a window to tune film characteristics like microstructure, porosity, film stress or deposition damage as well as electrical and optical properties.

Particularly well suited for complex materials of the future

Another key advantage of PLD compared to other vapor deposition technologies is the possibility to deposit complex material systems with or without volatile elements, maintaining a good stoichiometric transfer of the material from target to substrate. Difficult materials like LiNbO3 and KNN are easily deposited using PLD.

What about PLD and particles?

We disrupt the widespread premise that PLD-particles are blocker for Semicon manufacturing. Particle reduction patents form the core of Solmates’ IP. Solmates has been able to keep up with its aggressive particle reduction roadmap, as depicted in 2017. Feedback from customers about device yield has be positive.

A possible explanation is that PLD particles, ejected from the target during laser ablation, have the same composition as the surrounding deposited layer. Will this hold for your devices? There is only one way to find out.

Solmates PLD as a yield booster

Utilizing the local and pulsed nature of the deposition, Solmates can help solve costly manufacturing issues. A prime example is the control over film stress, where Solmates can ensure best-in-class uniformity over the entire wafer. If desired, these controls can be used to compensate for non-uniformities in other manufacturing steps, providing manufacturers a tool to boost their manufacturing yields.

Superior quality at a fraction of the cost

For most materials, Solmates can deliver volume manufacturing solutions at a fraction of the Cost-per-Wafer compared to other technologies. With PVD-like throughputs, the main differentiator is the productive ceramic targets. Read more about ceramic targers on our Scanramics page.