By combining high temperature and gas injections, it’s possible to modify the physical, optical or electrical properties of materials. For example, O2 or H2O ambient are used to grow silicon dioxide on Si. Inert ambient (N2, Ar)is used to densify layers or to activate and redistribute dopant impurities introduced previously by ion implantation. N2/H2 is used for aluminum sintering.
Silicon Oxidation: is the exposure of silicon (or polysilicon) to the action of gas oxidants (O2- termed dry oxidation, H2O – termed wet oxidation) at high temperatures (800-1150C). Part of the silicon of the surface (layer) is consumed and transformed in SiO2 so the starting thickness of the silicon layer is reduced (roughly 50% of the thickness of the obtained silicon dioxide); it can be used for thinning silicon micro-nanostructures. SiO2 layers can be ancillary used to interpose a dielectric barrier or as an etching or implanting mask.
Annealing processes: An annealing is a thermal process in which the substrates are exposed to different temperatures, times and environments depending on the pursued objective such as the post-implant annealing for impurities activation, the fluidization of interlevel dielectric layers, annealing of aluminum layers for contacts formation and the densification of different deposited layers
RIE is used to etch various materials under vacuum in the presence of reactive ions. The sample to be etched is placed in a vacuum chamber and gas is injected into the process chamber via a gas inlet in the top electrode. The lower electrode is negatively biased and a single RF plasma source determines both the ion density and their energy.
XPS is a surface spectroscopic technique for quantitative measurements of the elemental composition or stoichiometry and the chemical state of the present elements, like their oxidation state and chemical bonds. XPS is highly surface sensitive, giving chemical and binding energy information from the a narrow region close to the surface.
Ultraviolet lithography also known as optical or photolithography is the most commonly used patterning technique in microfabrication. A photosensitive material (photoresist) is spin-coated onto the substrate to be patterned. The photoresist is illuminated with UV light through a photomask which contains the relevant geometric patterns.
A set of classical microelectronic processes for deposition, of ancillary materials that are co-adjuvant to the obtention in the micro or nano domain of the functional materials that are the object of the Growth and Synthesis installation. It includes LPCVD and PECVD layers deposition or deposition of metal layers by PVD.
In SEM a beam is scanned over a sample surface while a signal from secondary or back-scattered electrons is recorded. SEM is used to image an area of the sample with nanometric resolution, and also to measure its composition, crystallographic phase distribution and local texture.