High performance silicon-based extreme ultraviolet (EUV) radiation detector for industrial application
ABSTRACT Silicon-based p+n junction photodiodes have been successfully fabricated for radiation detection in the extreme ultraviolet (EUV) spectral range. The diode technology relies on the formation of a front p+ active surface region by using pure boron chemical vapor deposition (CVD), which grows delta-like B-doped layers on Si substrates. Therefore, the technique can ensure defect-free, highly-doped, and extremely ultra shallow junctions that significantly enhance the sensitivity to UV radiation with respect to commercial state-of-the-art detectors, as confirmed by near theoretical responsivity (0.266 A/W, at 13.5 nm radiation wavelength). Outstanding performance has also been achieved in terms of extremely low dark current (< 50 pA, at a reverse bias of 10 V) and pulsed response time (< 100 ns) for 0.1 cm2 large area devices. In addition, the fabricated photodiodes exhibit negligible degradation to high-dose radiation exposure. Owing to these features, the presented photodiode technology, which profits from low cost, reduced complexity, and full compatibility with standard Si processing, offers a reliable solution for the implementation of detectors in industrial applications based on EUV radiation, such as next-generation 13.5 nm wavelength lithography.
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ABSTRACT: Recently, silicon-based ultrashallow junction p+n photodiodes fabricated by pure boron CVD technology (Pure-Bdiodes) were evaluated for detection in the Extreme Ultra-Violet (EUV) spectral range spanning from 3 nm to 15 nm. A near-theoretical responsivity (0.265 A/W) has been achieved at a wavelength of 13.5 nm, which is the operating wavelength of the next-generation lithography systems. Besides the outstanding optical performance stability already reported, in this paper, the electrical performance stability of PureB-diodes is characterized. The experimental results show that the main reason for the increasing EUV-induced dark current is the radiation-caused damage along the Si-SiO2 interface. However, this damage can be minimized by introducing a silicon nitride layer to the surface-passivation layer stack.IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society; 01/2012
Conference Paper: On the uniformity of pure-boron-layer depositions[Show abstract] [Hide abstract]
ABSTRACT: In this paper, the uniformity of PureB-layers deposited on photodiode surfaces of a segmented photodetector is investigated and discussed. Low-energy E-beam (LEEB) measurements have been carried out to study the uniformity and PureB-layer thickness variations over the anode surface area. It can be conclude that the PureB-layer is thinner in the middle and thicker at the edges of the opening windows where it is adjacent to oxide on the one side, and it is thickest at the corners of the window where it is adjacent to oxide on two sides. This shows the effect of the oxide surfaces (a so-called loading effect) around the openings on the thickness of the PureB-layer.ICT.Open: Micro technology and micro devices (SAFE), Veldhoven, The Netherlands; 11/2011
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ABSTRACT: The electrical and optical performance of silicon pure-boron (Pure-B) diode is investigated in relationship to the thermal processing used after formation of the PureB chemical-vapor-deposition layer that creates otherwise extremely ultrashallow p+-n junctions. The measured responsivity of PureB diodes is high and stable in the deep ultraviolet (UV) and vacuum UV spectral ranges, covering the spectrum from 220 down to 50 nm. Results are presented, showing that a very high surface charge collection efficiency can be obtained owing to a strong surface electric field resulting from a doping profile that is steep and without roll-off right up to the Si surface.IEEE Transactions on Electron Devices 11/2012; 59(11):2888-2894. DOI:10.1109/TED.2012.2210225 · 2.36 Impact Factor