In-situ Characterization of Atomic Layer Deposition (ALD)

Datum

26.06.2018

Zeit

15:00 - 16:00

Sprecher

Prof. Jiyoung Kim

Zugehörigkeit

Professor of Materials Sci. & Eng., The University of Texas at Dallas

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Ines Firlle

Beschreibung

Atomic Layer Deposition (ALD) has been widely utilized to deposit high quality high-k dielectrics with ultra-precise thickness controllability. However, during the initial few cycles of ALD, metal precursors and reactants are exposed to different environments because of a substrate unlike in the middle of ALD process. Anomalous initial growth behaviors are frequently observed at the initial ALD process. As devices are being continuously scaled down sub-10 nm node, it is critical to understand impacts of initial ALD process on interface characteristics as well as high-k dielectric deposition. Precursors and reactants for high-k dielectrics frequently exhibit strong interactions with a channel substrate, such as Si and III-V, during the first few cycles of ALD. Particularly, some of ALD precursors show a very high reactivity (or catalytic behavior) with a substrate at a processing temperature. For examples, La(fmd) enhances formation of La-silicate on Si substrate, while TMA (Trimethyl-Al) effectively remove native oxide at GaAs surface. On the other hand, some 2-D materials with hydrophobic nature, such as graphene and Mo2S, etc., would prevent appropriate adsorption of reactants on the basal plane, which causes non-uniform nucleation. If a chemical functionalization technique is applied to improve ALD nucleation process, performances of the channel would be frequently degraded. In this presentation, I am going to introduce in-situ XPS system clustered to thermal ALD to investigate surface reactions during the initial few half cycles of ALD on Si and III-V substrates. I will also discuss in-situ electrical characterization on 2D devices for initial few half cycles of ALD process.

Links

• Seminars at the IFW

Letztmalig verändert: 26.06.2018, 02:06:18