Prikaz stanja silicijevih MOS upravljanih učinskih sklopova i PiN ispravljača

Revolutionary advances and developments have been made in power semiconductor device technologies during the last decades which have allowed the improvement of power electronic systems in terms of their efficiency and reliability. The advent of MOS-gated power switches such as the power MOSFET and the IGBT showing high input impedance has been a real breakthrough in the design and fabrication of power electronic systems. This paper reviews the recent progress in the development of Si MOS-gated power devices and rectifiers. The evolution of these devices’ technologies together with the introduction of revolutionary device concepts is also discussed. Concretely, the introduction of trench technologies for power MOSFETs and the use of the super-junction concept for breaking the 1D-silicon limit are highlighted. Developments in IGBTs such as those based on the use of thin wafers and strategies for optimising the plasma distribution in PT IGBTs during the on-state are also addressed. Finally, advances in PiN diode technologies including new concepts for both the anode and the cathode structures are also reviewed. These approaches have allowed the reduction of the PiN total losses and a soft reverse recovery behaviour, leading to a more rugged device.U posljednjim desetljećima svjedočimo razvoju sustava učinske elektronike u pogledu povećanja efikasnosti i pouzdanosti. Napredak je omogućen zahvaljujući izvanrednom napredku koji je postignut na području učinskih poluvodiča. Pojava MOS upravljanih učinskih sklopova s visokom ulaznom impedancijom, kao što su MOSFET i IGBT, rezultirao je probojem u projektiranju i proizvodnji sustava učinske elekronike. Ovaj članak daje uvid u napredak koji je u posljednje vrijeme ostvaren u razvoju silicijeve MOS upravljane učinske elektronike i ispravljača. Uz dosadašnji razvoj tehnologije navedenih komponenata, u članku je uključen i osvrt na revolucionarne koncepte budućeg razvoja. Konkretno, u radu su objašnjene tehnologija rova za MOSFET i korištenje koncepta super spoja za probijanje granice jednodimenzionalnog silicija. Razmatrana su i poboljšanja IGBT-ova koja se baziraju na uporabi tankih pločica a strategijama optimiranja distribucije plazme u PT IGBT-ovima za vrijeme aktivnog stanja. Konačno, prikazan je i napredak u tehnologiji PiN dioda koji uključuje nove strukturalne koncepte katode i anode. Ovi pristupi su omogućili smanjenje ukupnih gubitaka PiN diode i blagu dinamiku reverznog oporavka, što rezultira povećanjem robusnosti sklopa

Humidity sensitivity of large area silicon sensors: Study and implications

The production of large area sensors is one of the main challenges that the ATLAS collaboration faces for the new Inner-Tracker full-silicon detector. During the prototype fabrication phase for the High Luminosity Large Hadron Collider upgrade, several ATLAS institutes observed indications of humidity sensitivity of large area sensors, even at relative humidities well below the dew point. Specifically, prototype Barrel and End-Cap silicon strip sensors fabricated in 6-inch wafers manifest a prompt decrease of the breakdown voltage when operating under high relative humidity, adversely affecting the performance of the sensors. In addition to the investigation of these prototype sensors, a specific fabrication batch with special passivation is also studied, allowing for a deeper understanding of the responsible mechanisms. This work presents an extensive study of this behaviour on large area sensors. The locations of the hotspots at the breakdown voltage at high humidity are revealed using different infrared thermography techniques. Several palliative treatments are attempted, proving the influence of sensor cleaning methods, as well as baking, on the device performance, but no improvement on the humidity sensitivity was achieved. Furthermore, a study of the incidence of the sensitivity in different batches is also presented, introducing a hypothesis of the origins of the humidity sensitivity associated to the sensor edge design, together with passivation thickness and conformity. Several actions to be taken during sensor production and assembly are extracted from this study, in order to minimize the impact of humidity sensitivity on the performance of large area silicon sensors for High Energy Physics experiments