Position for a Project Assistant Reactive species transport inside nanometric structures on wet-...

Reactive species transport inside nanometric structures

on wet-processed silicon wafers

The company Lam Research develops and manufactures single-wafer wet-processing devices for the

global semiconductor industry. The spin processing tools are designed for a highly controlled deposition of

specific cleaning, etching, and stripping chemicals on the rotating semiconductor wafers. The working liquid

is supplied through a vertical jet moving above the rotating wafer (see Figure 1). The ongoing miniaturization

of the surface structures makes it increasingly difficult to attain the desired quality of the process result.

For mastering this challenge, one needs a reliable comprehensive description of the relevant multi-scale

transport phenomena, ranging from the macro- and microscopic liquid film flow scales on the rotating substrate

down to smallest molecular scales inside the nanometer-size channel structures (vias, see Figure 2)

fabricated by the etching process. The present project shall develop a computational model for predicting

the convective/diffusive transport of reactive species on their way from the liquid film supply at the entrance

down to the bottom of the via, where these agents are supposed to chemically dissolve and remove all

residues from the prior etching. Starting from an already existing model for the macroscopic on-wafer

transport of mass, momentum and heat in the rotating thin film, the numerical modelling shall be extended

to the nanoscopic molecular diffusive transfer mechanisms inside the via, including chemical reactions.

Measured residue amounts from via-bottom reactions are used for model validation.

The project is carried out within the framework of the COMET centre of excellence “Centre for Electrochemistry

and Surface Technology (CEST)” Austria, with the industrial partner Lam Research AG, located at

Villach (Austria). The academic partner, the Institute of Fluid Mechanics and Heat Transfer at Graz University

of Technology, will supervise the candidate based on the scientific content of the project work.

Starting date: Any time from now, at the earliest convenience
Duration: 3 years