Atomic Layer Deposition for Lancaster Quantum Technology Centre Cleanroom

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The award will be used for the acquisition of a piece of advanced materials fabrication equipment for a process called atomic layer deposition (ALD). As the name implies, ALD is capable of depositing materials one atomic layer at a time. ALD films are grown by exposing a sample surface to organic gaseous chemicals (called precursors), that contain the required elements for the material of choice, and react with the surface such that just one layer of atoms is deposited. A very common example is the insulating layer aluminium oxide. Organic molecules with single aluminium atoms (trimethylaluminum) are introduced into a chamber that is under vacuum. After waiting for it to react with the surface, excess gas is removed, and then the aluminium is oxidised, e.g. with water vapour. Repeating this cycle multiple times allows the build-up of layers of very high-quality material of precise thickness. Furthermore, since the process is controlled by the chemical reaction between the precursor gas and the sample surface, rather than a line-of-sight method where the materials are somehow aimed at the sample (as is the case with some other deposition methods), the entire surface is coated uniformly irrespective of its topology. ALD is very widely used in research and commercial production, especially in the microelectronics industry. For example, it is used to make the capacitors that store the charge in DRAM and the dielectric layers in the transistors that make up computer processors. In Lancaster ALD will be used to complement and enhance existing equipment in the Lancaster Quantum Technology cleanroom, for a wide range of research programmes in condensed matter and materials physics, materials chemistry and engineering. The equipment will benefit at least 18 members of academic staff from the Departments of Chemistry, Engineering and Physics, their research assistants and research students. It will also be available to external users from other universities and from industry.