Thomas Leese

Volatility and vapourisation characterisation of new precursors

The introduction of new chemicals into semiconductor production processes is an expensive, time consuming exercise. A key parameter required to ensure equipment set up is well suited to the source from the outset of trials is reliable precursor volatility data. In this paper we present the latest vapour pressure values for the technologically interesting Hf and Ru precursors and corresponding thermogravimetric analysis results. A discussion on the interpretation of the values obtained highlights the careful considerations required to ensure promising source materials are not ruled out prematurely.

An Ab Initio Evaluation of Cyclopentadienyl Precursors for the Atomic Layer Deposition of Hafnia and Zirconia

Thin film dielectrics based on hafnium or zirconium oxides are being introduced instead of silica to increase the permittivity of insulating layers in nanoelectronic transistor and memory devices. Atomic layer deposition (ALD) is the process of choice for fabricating these films, and the success of this method depends crucially on the chemical properties of the precursor molecules. Much promise is shown by Hf and Zr metallocenes, i.e. precursors that contain cyclopentadienyl (Cp) ligands [1].