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This study examined MgZnO thin films grown on quartz substrates using radio frequency magnetron sputtering. These films with varying Mg content were used to fabricate metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors (PDs). The best sample with optimized properties was obtained using a Mg content of 20%. The relatively high Mg content could effectively suppress the dark current to a value of the order of 10 −13 A. The PD exhibited an on-off ratio of seven orders of magnitude; its photo-responsivity increased with the increasing Mg content, which caused the suppression of the dark current. The UV-to-visible rejection ratio could be up to five orders of magnitude. Furthermore, the noise equivalent power (NEP) and the normalized detectivity (D * ) of the PD fabricated with 20% Mg were determined as 6.6 × 10 −15 W and 6.5 × 10 −14 cmHz 0.5 W −1 , respectively. These results indicate that an increase in the Mg content could reduce the dark current and the noise by effectively suppressing the donor-like defects.In recent years, ultraviolet (UV) photodetectors (PDs) have attracted considerable interest owing to their newly developed commercial applications in areas such as flame sensing, missile detection, and communications. 1 As an oxide semiconductor material exhibiting a continuous tunable wide bandgap from 3.37 eV to 7.8 eV, wurtzite MgZnO has demonstrated its versatile functionality in various device applications. 2,3 Thus, research into novel ZnO-related materials has increased. MgZnO is similar to aluminum gallium nitride (AlGaN); it is an ideal material for UV photodetectors due to its wide band-gap, high radiation hardness, and low growth temperatures. In addition, this material is abundant in nature, inexpensive, and eco-friendly. Moreover, Mg has a stronger affinity toward oxygen than to Zn in ZnO, which leads to a decrease in the number of zinc interstitials and oxygen vacancies owing to the higher ionic character of the Mg-O bonds than that of the Zn-O bonds (the fractional ionic character is 0.61 for ZnO and 0.84 for MgO). 4,5 The ionic radii of Mg 2+ and Zn 2+ are similar (Mg 2+ : 0.57 Å and Zn 2+ : 0.60 Å). It has been reported that the addition of Mg 2+ to Zn 2+ site did not cause significant lattice disorder, and films of Mg x Zn 1−x O could be deposited up to x = 0.33 without segregation of the MgO phase. 6 Such wide and tunable bandgap is expected to enable MgZnO-based UV photodetector to be applicable. Till now, MgZnO-based UV photodetectors have been fabricated using different methods, such as metal organic chemical vapor deposition (MOCVD), RF-sputtering, and molecular beam epitaxy (MBE). 7 MgZnO-based UV photodetectors have been fabricated with various types, such as PN junction, PIN Schottky barrier and MSM UV photodetector. 8-10 Furthermore, MSM photodetectors have several attractive features that make them ideal candidates for space applications, such as a low dark current, high responsivity, large bandwidth, and low noise densities. Solar or visible-blind MgZnO PDs have been fa...

In this study, the trap properties of composite Hf 0.83 Zr 0.17 O 2 high-k gate stack p-type MOSFETs (pMOSFETs) were investigated by simultaneous low-frequency (1/f ) noise and random telegraph noise measurements. Compared with pure ZrO 2 pMOSFETs, the interface property and drive current of Hf 0.83 Zr 0.17 O 2 pMOSFETs were both improved, and the depth of the effective centroid of the fixed charges was close to the insulator/ semiconductor interface. This result indicated that the trapping behavior of hole capture from a ZrO 2 film can be suppressed by mixing the film with a HfO 2 film. Consequently, comparable oxide trap densities and trapping depths between Hf 0.83 Zr 0.17 O 2 and HfO 2 pMOSFETs can be seen. In addition, it was found that the unified model can appropriately interpret the 1/f noise mechanism in Hf 0.83 Zr 0.17 O 2 pMOSFETs.

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In this study, the impact of aluminum ion implantation on 1/f noise characteristics and random telegraph noise (RTN) in high-k/metal gate (HK/MG) p-type metal–oxide–semiconductor field-effect transistors (pMOSFETs) was investigated. Aluminum ion implantation (Al I/I) into TiN/HfO2/SiO2 was implemented to tune an effective work function (EWF) in pMOSFETs without EOT increase complicated processes. RTN and 1/f results revealed that regardless of the implanted dose, HK/MG devices with Al I/I exhibit lower slow oxide trap densities than the control devices, which are responsible for the reduced trap position (x t) from the SiO2 interfacial layer (IL)/Si interface. For the HK/MG devices with different implanted doses, no significant differences in trap properties were observed.