KE500EI Kenosistec electron-beam evaporator

Deposition and Microfab Facility of CISUP-University of Pisa
The Deposition and Microfab Facility of CISUP is an integrated laboratory well aligned with the scientific practice and good management standardized at international level. The laboratory is built around two major pieces of equipment for the deposition of thin films made of different classes of materials (oxides, metals, and organic compounds) on whatever type of substrate. The current technologies for thin-film deposition allow a surface or a sample to be covered by one or more layers of a desired material, with typical thickness values ranging from a few nanometers to about 100 micrometers. Crucial in semiconductor, photovoltaic, and optoelectronic industries, being capable of depositing a material with high degree of control on its thickness and stoichiometry is also important for many other scientific fields of modern science. The CISUP Facility comprises both thermal and electron/ion beam deposition methods, both belonging to the class of physical vapor deposition (PVD) technologies. Briefly, a substrate is covered by the material delivered by a target within a high-vacuum chamber. Methods developed in the laboratory include both electron-beam and thermal deposition technologies.

Kenosistem KE500EI

Deposition system with twin electron source and ion source, suitable for co-deposition processes of, among others:
(a) dielectrics: silica, titania, alumina, hafnia, tantala;
(b) semiconductors: silicon, germanium;
(c) metals: aluminum, nickel, copper, gold, titanium, silver.
The KE500EI equipment is a single batch system mainly designed for R&D applications that require versatility and facility of use. The process chamber is built with AISI304 stainless steel, and has a height larger than 0.9 m, which is at the base of highly uniform sample coverage. The chamber is provided with an internal shield, easily removable for effective cleaning. The chamber mounts several spare flanges for additional services or for possible future implementations, and it is provided with a water cooling line. The substrate holder is designed to carry up 1 wafer of 8”. Smaller substrates or irregular pieces of substrate can be placed on the substrate holder, enabling high versatility in terms of usable samples and targeted applications. The system carries one twin-electron beam gun source with 10 kW and 6 kW emitters, respectively, with six crucibles, an extra ion source for sample cleaning and assisted-deposition, direct water cooled brazed version with 20 cc capacity. Quartz lamps are used to support deposition processes up to 800°C. A powerful primary pump and turbo pump allow one to reach quickly the required high degree of vacuum, and a load lock provides better cleanliness of the process chamber, hence cleaner and better-controlled deposition and faster cycle time. The whole system is under control of PLC and a PC is used for the management of human-system communication.

Infrastructure and laboratory implementation

The Deposition and Microfab Facility of CISUP-University of Pisa is located in the Lab. 8 at the Department of Physics (Building B, Pontecorvo Area, ground floor). The Department of Physics has further developed the infrastructure serving the Facility, improving the reflectivity of the lab windows against solar light (to enhance the comfort in the lab and reduce thermal changes that may decrease the throughput of nanotechnology processes). A dedicated nitrogen supplier will be installed soon

Scientific fields addressed

PVD processes are studied and developed in several scientific fields, aiming at relating deposition parameters (temperature, deposition rate, gas flows, etc.) of materials with the resulting film properties. The CISUP Facility is also aimed at enabling the fundamental investigation of the mechanisms of growth and supramolecular organization of advanced materials (both inorganic and organic) in thin films (clustering, crystallization onset at nanoscale, self-assembly, -stacking of molecular materials, formation of J- and H-aggregates by light-emitting molecules, formation and relaxation dynamics of ultrastable glasses, etc.). The laboratory, integrating different deposition methods in a unique environment, can be a valuable platform for developing devices and applications in optics, electronics, optoelectonics (including flexible and wearable devices), as well as for life-science, biomedical and implantable components. Here are a few examples:
> Optoelectronics and optics: multilayers for optics and photonics, laser microcavities, litographically-defined waveguides, metamaterials and optomechanics. An exemplary collaboration is already set-up with the Dept. of Physics and INFN in the Virgo framework (advanced layered materials for low-noise mirrors boosting the detection of gravitational waves).
> Flexible electronics: high-k dielectrics for organic and hybrid field-effect transistors, organic and hybrid LEDs, devices based on 2D-materials and their heterostructures, wearable electronics, flexible sensors for both low- and high-energy physics and engineering.
> Life-sciences and biomedical applications: biocompatible films, functionalization of microfluidics devices, lab-on-chip, surface coatings and scaffolds for tissue engineering. Sensors for body-sensor networks and integrated chips for optogenetics.
> Conservation of cultural heritage: thin organic films for protecting artifacts against polluting compounds and bio-deterioration, permanent or disposable layers to control surface hydrophobicity, super-hydrophobic and ice-phobic surfaces.