Project description
Vertical epitaxial microcrystal growth on patterned silicon yields unprecedented properties
Silicon will remain the workhorse of many microelectronic and microphotonic devices. Integration of various other semiconducting materials on the silicon substrate is often achieved with epitaxial growth, creating a thin film. The EU-funded microSPIRE project will develop a novel deposition approach, vertical hetero-epitaxy (VHE), that exploits the patterning of conventional silicon substrates and epitaxial deposition. This will enable the self-assembly of arrays of vertically elongated germanium and gallium arsenide epitaxial micro-crystals with unparalleled structural and electronic properties. The microSPIRE approach will be demonstrated with innovative single-photon detectors in the infrared regime and tested for breast imaging and optical assessment of breast cancer risk.
Objective
µSPIRE aims at establishing a technological platform for homo- and hetero- structure based photonic and electronic devices using the self-assembling of epitaxial crystals on patterned Si substrates.
Emerging micro-electronic and photonic devices strongly require the integration on Si of a variety of semiconducting materials such as Ge, GaAs, GaN and SiC, in order to add novel functionalities to the Si platform. µSPIRE pursues this goal employing a novel deposition approach, which we termed vertical hetero-epitaxy (VHE). VHE exploits the patterning of conventional Si substrates, in combination with epitaxial deposition, to attain the self-assembly of arrays of Ge and GaAs epitaxial micro-crystals elongated in the vertical direction, featuring structural and electronic properties unparalleled by “conventional” epitaxial growth.
As a concrete demonstration of VHE potentialities, we will deliver a complete set of novel photon counting detectors: VHE micro-crystals will be used as the elementary microcells for single-photon detectors with performances far beyond those of current state-of-the-art devices, namely:
- High photon detection efficiency (> 80%), thanks to the use of several µm thick micro-crystals;
- High photon-number-resolving capability, thanks to the high density of micro-crystals;
- High fill-factor (> 90%), thanks to the almost complete surface coverage attained by VHE;
- Extended sensitivity from visible (350 – 900 nm) to NIR (800 – 1800 nm) and MIR (up to 10µm), thanks to the integration on Si of Ge and GaAs quantum wells.
As a first action towards real applications, the Si and Ge devices will be tested on phantoms closely mimicking breast tissue in order to assess the improvement in signal level with respect to state of the art detectors, and investigate the potential extension to a presently unexplored, but appealing, long-wavelength spectral range (1500nm+) of breast imaging and optical assessment of breast cancer risk.
Fields of science
Not validated
Not validated
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcomputer hardwarequantum computers
- natural sciencesphysical scienceselectromagnetism and electronicssemiconductivity
- natural sciencesmathematicspure mathematicsgeometry
- natural scienceschemical sciencesinorganic chemistrymetalloids
- natural sciencesphysical sciencestheoretical physicsparticle physicsphotons
Programme(s)
Funding Scheme
RIA - Research and Innovation actionCoordinator
20133 Milano
Italy