The interest for high performance UV sensors for operation in the deep UV regions of the spectrum is growing more and more interesting. This arises from the increasing industrial use of intense laser sources emitting in this spectral region for applications like micro-machining and ULSI photolithography. Such applications require detectors with a long lifetime that conventional semiconductors can’t offer. Owing to the high cohesive energy, diamond appears as the elective material for such kind of application. Thus diamond UV sensors are under development with the aim of improving their performance. High quality, 1 cm2 large and 0.8 mm thick, polycrystalline diamond deposited by a microwave CVD process has been used in this work. Thin chromium film has been realized by physical vapour deposition together with coplanar Silver contacts on the diamond surface, chemical mechanical polished to reduce the surface roughness. Fine line photolithography has been then used to define Chromium structures with resistance values in the kW range. A Neweks PSX100 ArF laser (4.5 mJ per pulse, FWHM=3 ns, 10-100 Hz, spot size 2x3 mm2) has been used to shine light on the realized devices and to test their performances in respect to the beam point stability and intensity variations for photons fluxes between 0.2 and 2.0 mJ. The output signal has been recorded as the voltage across the 50 W input impedance of a LeCroy Wavepro 960 digital sampling oscilloscope coupled to the device by means of a high speed buffer amplifier. Detector performances have been found strongly dependent on the shape and intensity of the laser beam, as well as by the design parameters of the detector. To obtain the best performances in terms of linearity and rejection to the beam intensity a mathematical model for the dependence of the detector output on the design and working parameters has been studied, and the output predicted by the model has been compared with the experimental results obtaining very good agreement.
Mazzeo, G., Prestopino, G., Salvatori, S., Conte, G., Ralchenko, V. (2004). Modeling and Testing of Deep-UV Position Sensitive Detectors.
Modeling and Testing of Deep-UV Position Sensitive Detectors
CONTE, Gennaro;
2004-01-01
Abstract
The interest for high performance UV sensors for operation in the deep UV regions of the spectrum is growing more and more interesting. This arises from the increasing industrial use of intense laser sources emitting in this spectral region for applications like micro-machining and ULSI photolithography. Such applications require detectors with a long lifetime that conventional semiconductors can’t offer. Owing to the high cohesive energy, diamond appears as the elective material for such kind of application. Thus diamond UV sensors are under development with the aim of improving their performance. High quality, 1 cm2 large and 0.8 mm thick, polycrystalline diamond deposited by a microwave CVD process has been used in this work. Thin chromium film has been realized by physical vapour deposition together with coplanar Silver contacts on the diamond surface, chemical mechanical polished to reduce the surface roughness. Fine line photolithography has been then used to define Chromium structures with resistance values in the kW range. A Neweks PSX100 ArF laser (4.5 mJ per pulse, FWHM=3 ns, 10-100 Hz, spot size 2x3 mm2) has been used to shine light on the realized devices and to test their performances in respect to the beam point stability and intensity variations for photons fluxes between 0.2 and 2.0 mJ. The output signal has been recorded as the voltage across the 50 W input impedance of a LeCroy Wavepro 960 digital sampling oscilloscope coupled to the device by means of a high speed buffer amplifier. Detector performances have been found strongly dependent on the shape and intensity of the laser beam, as well as by the design parameters of the detector. To obtain the best performances in terms of linearity and rejection to the beam intensity a mathematical model for the dependence of the detector output on the design and working parameters has been studied, and the output predicted by the model has been compared with the experimental results obtaining very good agreement.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
