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Recently a new type of device, the MAPS-on-diamond, obtained bonding a thinned to 25 μm CMOS Monolithic Active Pixel Sensor to a standard 500 μm pCVD diamond substrate, has been proposed and fabricated, allowing a highly segmented readout (10×10 μm pixel size) of the signal produced in the diamond substrate. The bonding between the two materials has been obtained using a new laser technique to deliver the needed energy at the interface. A biasing scheme has been adopted to polarize the diamond substrate to allow the charge transport inside the diamond without disrupting the functionalities of the CMOS Monolithic Active Pixel Sensor. The main concept of this class of devices is the capability of the charges generated in the diamond by ionizing radiation to cross the silicon–diamond interface and to be collected by the MAPS photodiodes. In this work we demonstrate that such passage occurs and measure its overall efficiency. This study has been carried out first calibrating the CMOS MAPS with monochromatic X-rays, and then testing the device with charged particles (electrons) either with and without biasing the diamond substrate, to compare the amount of signal collected.

The characteristics of two hybrid step-down charge-pump voltage regulators (2.5, 1.25 V) are presented. The regulators feature a current multiplication factor 4 and two capacitor banks structure which allows to work easily in the megahertz region and with currents up to 1.5 A. Attention has been dedicated to the study of the power efficiency as a function of the frequency, in particular to the charge transfer factor leading to the voltage efficiency which has been fully described in an analytic way. This has allowed to evaluate possible improvements of the present prototypes.

Micro-fabrication in diamond is involved in a wide set of emerging technologies, exploiting the exceptional characteristics of diamond for application in bio-physics, photonics, radiation detection. Micro ion-beam irradiation and pulsed laser irradiation are complementary techniques, which permit the implementation of complex geometries, by modification and functionalization of surface and/or bulk material, modifying the optical, electrical and mechanical characteristics of the material. In this article we summarize the work done in Florence (Italy) concerning ion beam and pulsed laser beam micro-fabrication in diamond., 14 pages, 5 figures

A wavelength dispersive system based on a flat crystal coupled to a CCD position-sensitive detector is described. The system, to be used in conjunction with an external beam facility for PIXE measurements, is particularly compact, easy to use, and has a useful energy range extending from about 4 to 13 keV. The performance of the system with respect to efficiency and energy resolution is studied as a function of different experimental conditions. Possible simple applications are briefly discussed.

In this work we report on the characterization with ionizing radiation sources of a CMOS active pixel radiation sensor (RAPS03) thinned down to 40um and bonded to a slice of diamond to form a rugged Silicon-On-Diamond structure. The bonding process is based on an innovative laser technique which scans the silicon-diamond interface with a 20 ps pulsed 355 nm laser beam. The goal of the work is to demonstrate that the bonding procedure does not damage the CMOS devices, paving the way for a possible alternative to bump bonding procedures between diamond substrates and readout chips. To this purpose, the Silicon-On-Diamond device and a standard (e.g. un-thinned) RAPS03 sensor have been tested in parallel with and without ionizing radiation sources (photons, electrons) to compare their characteristics and to study their differences. The Silicon-On-Diamond device has shown to be fully functional and no differences have been found between the responses of the two sensors, within the statistical variations due to the CMOS fabrication process.

A position sensitive detector for minimum ionizing particles is described. It is based on charge coupled devices (CCDs) area image sensors with single pixel sizes of 22 × 22 μm2. The operating frequency is 6.75 MHz and the total readout time for 2.3 × 105 pixels is about 40 ms. The devices are operated close to room temperature.