Specific Process Knowledge/Thin film deposition/Deposition of Aluminium Nitride: Difference between revisions
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=Aluminium Nitride (AlN)= | |||
Aluminum nitride (AlN) is a wide‑bandgap (~6.2 eV) ceramic that pairs very high thermal conductivity (> 200 W m<sup>-1</sup>K<sup>-1</sup> ), strong piezoelectric and acoustic properties, and a high dielectric breakdown field in a chemically inert, CMOS‑compatible matrix. | |||
It is deposited by reactive magnetron sputtering for dense, c-axis-oriented films widely used in RF devices, and by atomic layer deposition (ALD) when conformal, thickness-precise coatings are required on high-aspect-ratio or temperature-sensitive structures. | |||
In semiconductor technology, AlN acts as a nucleation or buffer layer for GaN power/high‑frequency devices, a robust passivation and diffusion barrier, and—when alloyed with Sc—to form ferroelectric AlScN for next‑generation non‑volatile FeFETs and piezoelectric MEMS actuators. | |||
Optically, its transparency from deep-UV to the IR and modest refractive index (~2.1) enable low-loss waveguides, UV LEDs/lasers, and protective or anti-reflective coatings that withstand high optical power and harsh environments. | |||
AlN’s strong piezoelectricity and high acoustic velocity underpin surface‑ and bulk‑acoustic‑wave filters, film bulk‑acoustic‑resonators, energy harvesters, and high‑Q MEMS resonators used in 5G RF front‑ends and timing devices. | |||
Beyond electronics and photonics, AlN substrates and thin films offer excellent thermal management for power modules, high-temperature, biocompatible passivation layers for sensors and implants, and mechanically robust coatings for corrosion and wear resistance, thereby cementing its role as a versatile thin-film material across semiconductor, optical, and engineering applications. | |||
= Deposition of Aluminium Nitride = | = Deposition of Aluminium Nitride = | ||
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==Reactive p-DC Sputtering of Aluminium Nitride (AlN)== | ==Reactive p-DC Sputtering of Aluminium Nitride (AlN)== | ||
[[Specific_Process_Knowledge/Thin_film_deposition/Cluster-based_multi-chamber_high_vacuum_sputtering_deposition_system | [[Specific_Process_Knowledge/Thin_film_deposition/Cluster-based_multi-chamber_high_vacuum_sputtering_deposition_system|Cluster Lesker]] is the best option for deposition of AlN, especially the Sputter-System Metal-Nitride(PC3) chamber, which has no history of oxygen. The process requires elevated temperatures and uses an Al substrate as a source. The films are highly textured. To improve quality, it is also possible to [[Specific Process Knowledge/Thin film deposition/Deposition of Scandium Nitride/ScN Reactive Sputtering in Cluster Lesker PC3|dope the AlN with scandium]]. At DTU Nanolab, there is an option to perform co-sputtering of both [[Specific Process Knowledge/Thin film deposition/Deposition of Scandium/Sc Sputtering in Cluster Lesker PC3|Sc]] and [[Specific Process Knowledge/Thin film deposition/Deposition of Aluminium/Al Sputtering in Cluster Lesker PC3|Al]] at different powers to get ScAlN thin films. | ||
==Comparison of the methods for deposition of AlN== | ==Comparison of the methods for deposition of AlN== | ||