Near-infrared waveguide-based nickel silicide Schottky-barrier photodetector for optical communications

Abstract

Integrated silicon-on-insulator waveguide-based silicide Schottky-barrier photodetectors were fabricated using low-cost standard Si complementary metal-oxide-semiconductor processing technology. The thin epitaxial NiSi2 layer formed by solid-state Ti-interlayer mediated epitaxy on the top of Si-waveguide absorbs light propagating through the waveguide effectively and exhibits excellent rectifying property on both p-Si and n-Si. NiSi2∕p-Si detectors with tapered geometry demonstrate dark current of ∼3.0nA at room temperature, responsivity of ∼4.6mA∕W at wavelengths ranging from 1520to1620nm, and 3dB bandwidth of ∼2.0GHz. The approaches for further improvement in responsivity are addressed.

All-Si photodetector for telecommunication wavelength based on subwavelength grating structure and critical coupling

“…7,12 This makes more photo-carriers arriving at the Si layer before being scattered in the silicide layer. 10,13 However, this approach may lead to a significant reduction in the optical absorption efficiency. To enhance the optical absorption efficiency as well as the IQE, one can integrate the IPE-PD into a resonator structure such as a microring resonator 14 or a Fabry-Perot cavity.…”

Silicon photodetectors based on internal photoemission effect: The challenge of detecting near infrared light

“…An indirect evaluation of the bandwidth of the detector was reported to confirm the operation speed potentialities. A bandwidth of about 3 GHz was measured by Zhu et al in (Zhu et al, 2008a) on a Schottky barrier based integrated photodetector, where the junction was achieved by a nickel silicide layer (NiSi 2 ) on silicon (Zhu et al, 2008b(Zhu et al, , 2008c (Fig. 13).…”

“…13. Schematic structure of waveguide-based silicide Schottky-barrier photodetector proposed by Zhu et al (Zhu et al, 2008b(Zhu et al, , 2008a In particular, the authors proposed the lengthening of a thin silicide layer on the surface of a SOI waveguide to achieve both a suitable optical absorption and an efficient photoexcitation of metal electrons or holes across the silicide/Si interface. A detailed analysis was reported www.intechopen.com Photodetectors 70 on the influence of the silicide layer dimension on the performances of both NiSi 2 /p-Si and NiSi 2 /n-Si diodes.…”

“…For the realization of photodiodes integrated in photonics circuits operating at wavelengths beyond 1100 nm silicon is not the right material because its transparency. In the last years, in order to take advantage of low-cost standard Si-CMOS processing technology, a number of photodetectors have been proposed based on different physical effects, such as: defect-state absorption (Bradley et al, 2005), two photon absorption (TPA) (Liang et al, 2002) and internal photoemission absorption (Zhu et al, 2008a). Physical effects, working principles, main structures reported in literature and the most significant results obtained in recent years were reviewed and discussed in our previous paper (Casalino et al, 2010a).…”

Microcavity Silicon Photodetectors at 1.55 μm

“…On the other hands, this transparency window limits the Si applications as absorbing material for infrared photodetection, so that the development of highperformance waveguide-integrated photodetectors on Si-CMOS platform has remained an imperative but unaccomplished task. In order to develop all Si photodetectors and to take advantage of the low-cost standard Si-CMOS processing technology without additional materials or process steps, a number of options have been proposed, in particular, the two-photon absorption (TPA) [9], the incorporation of optical dopants/defects with mid-bandgap energy levels into the Si lattice [10,11], and the internal photoemission effect (IPE) [12]. The IPE has been recently used also in silicon photodetectors realized with plasmonics structures [13,14].…”