The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

Recent years have witnessed a growing interest in detectors capable of detecting single photons in the near-infrared (NIR), mainly due to the emergence of new applications such as light detection and ranging (LiDAR) for, e.g., autonomous driving. A silicon single-photon avalanche diode is surely one of the most interesting and available technologies, although it yields a low efficiency due to the low absorption coefficient of Si in the NIR. Here, we aim at overcoming this limitation through the integration of complementary metal–oxide–semiconductor (CMOS) -compatible nanostructures on silicon photodetectors. Specifically, we utilize silver grating arrays supporting surface plasmons polaritons (SPPs) to superficially confine the incoming NIR photons and therefore to increase the probability of photons generating an electron-hole pair. First, the plasmonic silver array is geometrically designed using time domain simulation software to achieve maximum detector performance at 950 nm. Then, a plasmonic silver array characterized by a pitch of 535 nm, a dot width of 428 nm, and a metal thickness of 110 nm is integrated by means of the focused ion beam technique on the detector. Finally, the integrated detector is electro-optically characterized, demonstrating a QE of 13% at 950 nm, 2.2 times higher than the reference. This result suggests the realization of a silicon device capable of detecting single NIR photons, at a low cost and with compatibility with standard CMOS technology platforms.

Recent advancements in quantum technologies are fueled by the ability to engineer materials with specific quantum properties, enabling various applications. The nitrogen‐vacancy (NV) center in diamond is a key system for nanoscale sensors, capable of detecting weak magnetic fields with nanotesla‐range sensitivity. To achieve high spatial resolution and sensitivity, NV centers must be placed near the diamond surface. This study investigates the creation of NV defects in a pure chemical vapor deposition (CVD) diamond single crystal via broad‐beam ion implantation. The implantations are performed through thin (100 nm) SiO ₂ layers deposited by plasma‐enhanced CVD (PECVD). Both normal and oblique ion beam incidences are used, with the oblique incidence chosen to reduce the nitrogen ion penetration depth. Simulations show a subsurface NV center distribution, with the highest concentration near the surface; the expected trends are confirmed by angle‐resolved X‐ray photoelectron spectroscopy (ARXPS) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). This distribution extends to a depth of 30 nm. By adjusting the ion beam incidence angle, NV center density can be modulated. This work contributes to optimizing the fabrication process for shallow color centers through ion implantation using a screening layer.

Over the last few years, employment of the standard silicon microfabrication techniques for the gas sensor technology has allowed for the development of ever-small, low-cost, and low-power consumption devices. Specifically, the development of silicon microheaters (MHs) has become well established to produce MOS gas sensors. Therefore, the development of predictive models that help to define a priori the optimal design and layout of the device have become crucial, in order to achieve both low power consumption and high mechanical stability. In this research dataset, we present the experimental data collected to develop a specific and useful predictive thermal-mechanical model for high performing silicon MHs. To this aim, three MH layouts over three different membrane sizes were developed by using the standard silicon microfabrication process. Thermal and mechanical performances of the produced devices were experimentally evaluated, by using probe stations and mechanical failure analysis, respectively. The measured thermal curves were used to develop the predictive thermal model towards low power consumption. Moreover, a statistical analysis was finally introduced to cross-correlate the mechanical failure results and the thermal predictive model, aiming at MH design optimization for gas sensing applications. All the data collected in this investigation are shown.

Group-IV-related color centers in diamond are promising systems in the framework of solid-state quantum technologies. A key enabler for the integration of these emitters in real-world devices consists of their reliable fabrication by means of controlled engineering processes such as deterministic ion implantation. In this work, the formation yield of the negatively charged germanium-vacancy (GeV−) center in diamond upon keV ion implantation and subsequent thermal annealing was investigated. A systematic fabrication approach was adopted, exploiting focused ion beam technology to take advantage of nanometric spatial accuracy and a controllable implantation fluence. The photoluminescence analysis of the implanted spots, including single emitter characterization, enables the direct quantification of the GeV− center formation yield under the implemented fabrication approach.

The possibility of integrating plasmonic nanostructures directly on an active device, such as a silicon photodetector, is a challenging task of interest in many applications. Among the available nanofabrication techniques to realize plasmonic nanostructures, Focused Ion Beam (FIB) is surely the most promising, even if it is characterized by certain limitations, such as ion implantation in the substrate. In this work, we demonstrate the direct integration of plasmonic nanostructures directly on an active Si-photodetector by patterning a silver film with FIB. To avoid ion implantation and to therefore guarantee unaltered device behavior, both the patterning parameters and the geometry of the nanostructures were implemented by Montecarlo and Finite-Difference Time-Domain simulations.