LInking Growth dynamics with Atomistic process and stress generation during MEtal-on-iNsulaTor vapor deposition

The goals of the proposed project are to (i) gain a holistic and quantitative view of the atomistic mechanisms that govern morphology evolution during metal-on-insulator (MOI) deposition and (ii) establish the correlation between these mechanisms and film stress generation and evolution. These goals will be achieved via the following objectives:

Obj. 1: Establish the effect of atomic mobility and temporal profile of the deposition flux on the growth dynamics all the way from nucleation until formation of a continuous film.

Obj. 2: Study the influence of the energy of the deposition flux on growth dynamics and stress generation and evolution during MOI deposition.

Obj. 3: Use knowledge from Obj. 1 to identify and quantify atomistic mechanisms that govern film morphology evolution at the various film formation stages.

Obj. 4: Establish the correlation between forming mechanisms, morphology and stress generation and evolution.

The goals and objectives will be achieved by a research strategy that comprises the following key components:

• Thin film synthesis employing vapor fluxes that are tailored with regards to their temporal profile and energetics. Tailoring of the flux temporal profile shall mean growth using vapor fluxes with different time-averaged arrival rates (i.e., deposition rates), as well as pulsed vapor fluxes with well-defined width, frequency and amplitude. Pulsed fluxes have been shown to provide added means for controlling and understanding film growth evolution.
• In situ diagnostic tools (i.e., spectroscopic ellipsometry, 4-point-probe resistivity measurements, differential reflectivity, wafer curvature measurements) to study and establish the effect of the deposition conditions on the scaling behavior of characteristic morphological quantities—q_perc, q_cont and surface roughness (w)— as well as on intrinsic stress evolution at various film formation stages.
• Ex situ imaging tools (Transmission Electron and Atomic Force Microscopies) to determine morphology of the films and complement the in situ

A variety of noble metals (Ag, Cu, Au, Pd) deposited on amorphous SiO₂ substrates will be used as model systems as they are archetypes for MOI growth, while these metals exhibit distinctly different melting points allowing to effectively scan a wide range of atomic motilities during growth.