Gamma radiation sensing using ZnO and SnO2 thick film

2004 24th International Conference on Microelectronics (IEEE Cat. No.04TH8716), 2004

Materials Science and Engineering: B, 2004

Throughout this work tellurium dioxide (TeO 2 ), indium oxide (In 2 O 3 ), silicon monoxide (SiO), nickel oxide (NiO) and LaFeO 3 perovskite and their mixtures in different proportions in the forms of thin and thick films were used as materials for the radiation sensing layers. Detection of radiation was performed based on the fact that both electrical and optical properties of the materials undergo changes upon the exposure to gamma radiation. It was found that the optical band gap values decreased with the increase in radiation dose. Influence of radiation resulted in significant alterations of current-voltage characteristics in both thin and thick film devices.

Metal Oxide Films/Structures for Gamma Radiation Detection, 2017

In this work, aluminum oxide, nickel oxide films were prepared for the purpose of gamma radiation dosimetry using several deposition techniques. A significant change in the (I-V) measurements for the as deposited films, p-n junction film structures have been observed upon exposure to high and low gamma radiation doses which proofs the promising characteristics of these oxide films for gamma radiation dosimetry applications.

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2007

Radiation sensors based on metal oxide semiconductor (MOS) structure are useful because of their superior sensitivity as well as excellent compatibility with the existing microelectronic technology. In this paper, a systematic study of MOS capacitors built on pand n-type Si substrates with different SiO 2 thicknesses (10 nm, 50 nm, 100 nm and 240 nm) is presented. MOS device response to gamma radiation up to 256 Gray have been studied from the sensor application point of view. Variation of the radiation induced device response with oxide thickness, substrate type, applied bias and post annealing have been measured and discussed. Radiation induced charge in MOS devices is shown to be a strong function of the oxide thickness as expected. Application of a positive bias to the gate is found to enhance the device sensitivity for both n-and p-type devices. This is explained in terms of the involvement of the interface states in the sensing process. Devices have also been studied after repeated cycles of irradiation and annealing treatment under hydrogen atmosphere. Each cycle consists of gamma irradiation with 60 Gray dose and an anneal at 200°C for 30 min. The charging-discharging mechanism during these cycles is discussed.

IEEE Transactions on Nuclear Science, 2000

This paper presents a gamma radiation dosimeter built in a standard 0.35 m CMOS technology. The dosimeter, which occupies 300 150 m m of silicon area, gives a digital output signal of frequency proportional to the total dose. Experimental results up to 1.5 Mrads are presented. Measured low dose radiation responsivity is 84.7 Hz/Krad and sensitivity to temperature and supply voltage are 1.43 kHz/ C and 20.9 kHz/V, respectively.

SPIE Newsroom, 2007

Mixed metal oxide thin-film sensors can provide cost-effective real-time monitoring of radiation and toxic gases.

The dosimetry is one of the crucial techniques that are needed to assure personal safety and facilities security in the areas of high radioactivity as nuclear power plants or powerful experimental research infrastructure (LHC, XFEL, ITER). Until now, the common electronic dosimeters are based on the silicon diodes or field effect transistors what limits the measured dose value up to few Mrad, as the higher levels lead to the device saturation. The other techniques that allows for higher dose measurement (up to 100 Mrad and more) are based mostly on the variation of physic-chemical parameters of different materials but need the post measurement treatment of the sensor that has to be taken out of the monitored zone and use of the special equipment what makes the continuous measurement impossible. Moreover, in case of nuclear reactors the access to the radioactive zones is limited what leads to the measurement frequency in range of a few times per year. The solution that may overcome that problem is the use of the recently developed innovative concept of the passive sensors that are interrogated by the radar technique. Such a solution uses the small (millimeter sized) micro-resonators designed for the ultra high frequency (about 30GHz) that are connected to the antenna and serve as its load. Any change of the resonant frequency of the resonator may be detected as the shift in the radar echo of the antenna. The sensor is interrogated by the directional radar and the reflected signal is analyzed. The associate transduction principle is that the resonator changes its resonant frequency due to the variation of the specific measured physical value like temperature, pressure or humidity. In our case, we proposed to use the known principle of Hydrogen-pressure dosimeters (HPD) where the polymer material dehydrogenates under irradiation. However, using the MEMS technology we want to miniaturize it and combine with the RF pressure transducer, in order to obtain the miniature (about 4 mm square) passive dosimeter. The main advantages of such a system are the passive (battery less) operation mode and radar interrogation what assures the distant (few ten of meters) signal reading and real time monitoring.

Co-60 gamma irradiation responses of the Y 2 O 3 MOS capacitors were investigated, and initial assessment of the Y 2 O 3 dielectrics used in gamma radiation sensors was discussed. We analyzed the effects of applied radiation from flat-band and mid-gap voltage shifts, and also capacitance–voltage measurements were obtained before and after irradiation. It has been observed that the measured capacitance is almost constant with irradiation and the basic modification in flat band shifts toward more positive voltages due to negative charge accumulation, thanks to trap centers in the MOS capacitors. The reason of negative charge trapping in the devices structure may be attributed to ionized Yttrium atoms and cluster of the oxygen vacancies occurred by irradiation. Also, a linear dose flat band relation has been observed, and irradiation sensitivity was found to be 10.8 ± 0.43 mV/Gy for Y 2 O 3 calculated for five different capacitors, which is more sensitive than the conventional SiO 2 dielectric layers. The higher sensitivity is probably due to the high trapped efficiency in the Y 2 O 3 dielectrics. On the other hand, the generated oxide traps densities increase with irradiation while interface state density trend varies by irradiation. This behavior for interface states was attributed to the passivation of the dielectric layer from the semiconductor. The charge accumulation in the MOS capacitors is in the order of 10 10 –10 11 cm −2 for the given dose range. This did not cause any significant device degradation through its operation. Consequently, the irradiation does not significantly affect the device operation. Especially, for radiation measurements system with linear dose performance and sensitivity, Y 2 O 3 may be a promising future gate dielectric material candidate for radiation sensors in given radiation dose range.

2004

In this work, the use of mixed oxide materials, such as Manganese oxide (MnO) and Tellurium dioxide (Te02) in the form of thermally evaporated thin film structures, is explored for gamma radiation dosimetry application. All samples showed an increase in the values of current with the increase in the radiation dose up to certain dose levels. K. Arshak and 0. Korostynska are with Electronic

IEEE Sensors Journal, 2000

A prototype gamma radiation monitoring system based on In 2 O 3 SiO thick-film sensors array was designed. Four sensors had an identical pn-heterojunction structure with different material compositions. These sensors were subjected to gamma radiation emitted by 137 Cs source with an activity of 370 kBq. Changes in their current-voltage characteristics were recorded and compared. The performance parameters of the devices, such as sensitivity to radiation exposure and working dose region, were found to be highly dependent on the composition of the materials used. To cover a wider range of radiation and improve the overall sensitivity, an approach of using sensor arrays was utilized. A dynamic selection of the multiple sensors of various sensitivities and working dose ranges was implemented by applying a pattern recognition analysis.