OPTICAL PHOTOLITHOGRAPHY

Laser beam direct writing lithography (Reference persons: S. Di Franco, F. Roccaforte)

The Laser beam direct writing lithography from is equipped with a laser diode (wavelength 405 nm) and a high resolution pattern generator (up to 0.5 µm with 2 mm write-head). It can be used for low volume mask making or direct exposure of microstructures on basically any flat material coated with photoresist. The system allows to process samples of different size (from small pieces, 10 mm × 10 mm, up to 150 mm wafers) and arbitrary shape.

NANOLITHOGRAPHY

Electron beam lithography (Reference person: Giuseppe D’Arrigo)

The E-Line apparatus by Raith has the following characteristics:

• Schottky thermal-field emission filament,
• acceleration voltage: 100 V – 30 kV,
• beam diameter smaller than 2 nm at 20 kV,
• working distance: 2 – 15 mm,
• write field: 1 μm – 1 mm,
• sample size: 1 mm – 4 inches,
• interferometer stage with 2 nm positioning accuracy,
• minimum line width smaller than 20 nm (better than 10 nm achievable with negative resist overlay and stitching accuracy better than 20nm).

It is also equipped with:

• Electron Beam Induced Deposition-Modification system (EBID-EBIM for deposition of Pt, W, insulators, etc.) and with two Nano-Manipulators for in situ electrical measurements;
• Plasma Oxygen Etching System.

Nanoimprint lithography (Reference persons: S. Di Franco, F. Giannazzo)

The fromis a nanoimprinting lithography system, equipped both with the harm for “hot-embossing lithography” and for “UV-NIL”. It allows handling chip-size up to 40 mm and substrates up to 150 mm in diameter. Furthermore, it is equipped with a very high positioning accuracy stage (sensitivity ~1 mm), with optical alignment system. An apparatus for automatic polymer deposition is present. Temperature ramps up to 400°C with heating speed up to 10 °C/s and sensitivity of 1 °C, and forces up 50 N can be applied during imprinting.

Thanks to the high optical alignment resolution, samples positioning accuracy, controlled temperature and pressure ramps, this system has been employed also for high precision thermo-compression printing of novel materials (such us graphene and transition metal dichalcogenides) to a target substrate.

ETCHING EQUIPMENTS

Inductively coupled plasma etching (Reference persons: S. Di Franco, F. Roccaforte)

The is system for plasma etching of different materials (e.g., Si, SiO₂, Si₃N₄, GaN, SiC, AlN) with substrate size up to 12 inches. The system includes a cylindrical vacuum chamber, a helium back side coolable carrier to substrate handling, pumping system, plasma generation and a spectrometer to detection etching end point. A separate load-lock and pumping system allows the automatic loading and unloading of the substrates to the process chamber. Several reactive gases are used, such as chlorine, borane trichloride, sulfur hexafluoride and trifluoromethane.

GROWTH, DEPOSITION AND THERMAL PROCESSES

Metal sputtering system (Reference persons: S. Di Franco, F. Roccaforte)

The Q300T D Dual Target Sequential Sputtering System from Quorum Technologies is a fully automatic, large chamber, dual-head sputter coater, suited for many thin film applications and device fabrication. The dual-head configuration allows two different metals to be sequentially sputtered without the need to 'break' vacuum. Thin films depositions can be done both on small samples and on entire wafers up to 150mm in diameter. The system is equipped with a fully automatic touch screen control and a dual channel film thickness monitor module. The pressure in the chamber during deposition can be automatically set. A wide range of metals can be sputtered with the Q300T D (Au, Pt, Ni, Cr, Ti, Al, Ta, Mo, …).

DC Magnetron Sputtering (Reference person: A. Alberti)

DC magnetron sputtering system made by Kenotec (today Kenosistec). The high vacuum chamber (10^-9 Torr) is equipped with three metallic cathodes for sequential deposition of multilayer structures on 6 inches wafers, and with a station for etching procedures. It is currently used to deposit from thin (about 1 nm) to thick (larger than 1 µm) layers of nickel, cobalt, aluminum and titanium for applications in microelectronic devices such as MOS-transistors and Schottky diodes. The system is equipped with two additional inlets for oxygen and nitrogen injection into the deposition chamber for reactive deposition of nitride and oxide such as TiN and TiO₂ mainly used in microelectronics, photovoltaics and sensors architectures. In situ heating during deposition up to 250°C can be also applied by an integrated stage.

Inductively Coupled Plasma CVD (Reference person: G. Mannino)

This type of deposition improves considerably the capabilities of depositing a layer  by decomposition of precursors gas in plasma by coupling an inductive RF. Thanks to this approach one can have higher ionized species in the plasma up to one order of magnitude with respect to conventional plasma systems. This allows to reduce the deposition temperature down to room temperature producing layers on any substrate (including polymeric and glass substrates) with excellent electro-optical properties. Furthermore, the vertical and cylindrical configuration of the chamber allows maintaining the sample outside the plasma region ensuring no acceleration of charged species toward it. The sample surface is therefore is not damaged and better preserved. The system actually in use allows to deposit several material types (Si or C based) by these precursors: SiH₄, CH₄, N₂, N₂O, PH₃, TMB, NH₃.

Atomic Layer Deposition (Reference persons: R. Lo Nigro, S. Di Franco)

The Atomic Layer Deposition reactor PE ALD LL SENTECH Instruments GmbH enables the controlled deposition of ultra-thin conformal, pinhole- and particle-free films with excellent uniformity for a wide range of materials, including high-k dielectrics (Al₂O₃, HfO₂), nitrides (AlN) and nanolaminates (Al₂O₃/HfO₂ stacks) by thermal as well as plasma enhanced processing.

Depositions can be performed on 2, 4, 6 and 8 inches wafers as well as on small pieces having different sizes and shapes. Substrate stage and reactor wall temperature can be controlled up to 500°C and 150°C, respectively.

Deposition processes of high-k dielectrics on wide-bandgap semiconductors (SiC, GaN) and 2D materials (graphene, MoS₂) have been developed with this equipment.

Furnaces

• EATON Vertical Furnace (Reference person: S. Di Franco)

The laminar flow furnace by EATON allows annealing of silicon wafers up to 8 inches at temperatures up to 1250 °C in O₂, N₂ or Ar gas ambient.

• Rapid thermal annealing (Reference persons: S. Di Franco, M. Italia)