Clean Room
Nanoscale science and technology facility for integrated electronics
This facility provides a new class 10 (ISO4) clean room space equipped with all the state of the art nanofabrication facilities such as hot embossing nanoimprinting lithography (NIL) and UV NIL step and repeat, electron beam lithography (EBL) equipment by Raith for resist exposure, electron beam assisted local processing (e-line^(TM)) and nanomanipulation, inductive coupled plasma (ICP) etching with Cl and F chemistries up to 300 mm wafers, laser lithography, several equipment for metal and dielectric depositions, lamp, hot bench and horizontal ovens for annealings and processing for time going from spike annealing as long as 100 hrs, infrared laser apparatus for high temperature anneals in the milliseconds range.
Ultra high resolution electron beam lithography and nano-engineering workstation
In the clean room we have the e-line apparatus by Raith for electron beam lithography and electron beam assisted processing. Characteristics of the facility are:
- Schottky thermal-field emission filament
- beam diameter smaller than 2 nm at 20 kV
- acceleration voltage: 100 V – 30 kV
- working distance: 2 – 15 mm
- write field: 1 μm – 1 mm
- samples: 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
The apparatus is also equipped with an electron beam induced deposition system (for deposition of platinum, tungsten, insulators, etc.) and with two nano-manipulators for in situ measurements.
Staff contact: Giuseppe D'Arrigo
Nano-imprinting lithography
Nano-imprinting lithography is carried out by using the SUSS Microtech facility. The facility allows us to process silicon wafers up to 150 mm in diameter. It is equipped with a very high positioning accuracy stage, with a optical alignment system, and with an apparatus for in-situ polymer deposition. The facility can emboss by using a force as high as 50 N at a temperature of 400 °C.
Staff contact: Salvatore Di Franco
Thermal treatment facilities
The clean room is equipped with a laminar flow furnace by EATON which allows us to anneal 8 inches silicon wafers up to 1200 °C, and with a spike anneal apparatus by JIPELEC for very rapid thermal processes characterized by temperature ramp rates up as fast as 150 °C / s.
Staff contact: Salvatore Di Franco, Markus Italia
Laser beam lithography
The DWL 66 is a laser lithography system (helium-cadmium laser with wavelength 442 nm), with very high resolution pattern generator (up to 0.5 µm with 2 mm lens), for direct writing of microstructures and low volume mask making. The system includes : three optical lenses, 2 mm, 10 mm and 40 mm; an autofocus air gauge system that allows lithography even on transparent substrates; high resolution interferometer to control the position of the stage with high accuracy during the operation. The DWL 66 is also equipped with two cameras used for metrology and alignment purposes and this enables one to perform overlay exposures with high accuracy. The system allows one to process samples of different size (from small pieces, 10 mm × 10 mm, up to 6 inches wafer) and arbitrary shape.
Staff contact: Salvatore Di Franco
Inductively coupled plasma etching
The Roth & Rau Microsys 400 ICP-RIE (inductively coupled plasma) is a special system for plasma etching of different materials (e.g. Si, SiO2, Si3N4, GaN, SiC) at substrates of size up to 12 inches. The system includes a cylindrical vacum chamber, a helium back side coolable carrier to substrate handling , pumping system, plasma generation and a spectrometer to detection etching end point. A separete load-lock system (equipped with separate 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.
Staff contact: Salvatore Di Franco
High power Semiconductor laser facility
Semiconductor laser ensures high power in few milliseconds annealing. This equipment take the advantage typical of laser systems of heating materials with high ramp rates, up to 106 °C/s, but allows a careful control of the annealing temperature below the melting point. This results in effective crystallization of micron-thick amorphous Si layers and synthesis of Si nanocrystals for solar cells, full crystallization of hydrogen rich a-Si layers without void formation or film degradation and formation of highly active doped junction with no appreciable dopant diffusion. The system source is a CW 600 W GaAs diodes array which is focused on the sample reaching a maximum power density of 300 kW/cm2 and two step by step motors to control annealing time from 1 to 170 ms on wafers up to 8 inches.
Staff contact: Giovanni Mannino
