Recent Progress in the Understanding of Si-Nanostructures Formation in a-SiNx:H Thin Film for Si-Based Optoelectronic Devices

2011 ◽  
Vol 171 ◽  
pp. 1-17 ◽  
Author(s):  
Sarab Preet Singh ◽  
Pankaj Srivastava

There has been a rapidly increasing interest in the synthesis and characterization of Si- nanostructures embedded in a dielectric matrix, as it can lead to energy-efficient and cost-effective Complementary Metal-Oxide-Semiconductor (CMOS)-compatible Si-based light sources for optoelectronic integration. In the present contribution, first an overview of the SiOx as a dielectric matrix and its limitations are discussed. We then review the literature on hydrogenated amorphous silicon nitride (a-SiNx:H) as a dielectric matrix for Si-nanostructures, which have been carried out using silane (SiH4) and ammonia (NH3) as the reactant gases. Our studies demonstrate that the least amount of hydrogen in the as-deposited (ASD) a-SiNx:H films not only allows in-situ formation of Si-nanostructures but also stabilizes silicon nitride (Si3N4) phase. The recent advances made in controlling the shape and size of Si-nanostructures embedded in a-SiNx:H matrix by swift heavy ion (SHI) irradiation are briefly discussed.

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2454
Author(s):  
Yi-Kuang Yen ◽  
Chao-Yu Lai

Detecting the concentration of Pb2+ ions is important for monitoring the quality of water due to it can become a health threat as being in certain level. In this study, we report a nanomechanical Pb2+ sensor by employing the complementary metal-oxide-semiconductor microelectromechanical system (CMOS MEMS)-based piezoresistive microcantilevers coated with PEDOT:PSS sensing layers. Upon reaction with Pb2+, the PEDOT:PSS layer was oxidized which induced the surface stress change resulted in a subsequent bending of the microcantilever with the signal response of relative resistance change. This sensing platform has the advantages of being mass-produced, miniaturized, and portable. The sensor exhibited its sensitivity to Pb2+ concentrations in a linear range of 0.01–1000 ppm, and the limit of detection was 5 ppb. Moreover, the sensor showed the specificity to Pb2+, required a small sample volume and was easy to operate. Therefore, the proposed analytical method described here may be a sensitive, cost-effective and portable sensing tool for on-site water quality measurement and pollution detection.


2019 ◽  
Vol 9 (2) ◽  
pp. 255 ◽  
Author(s):  
Quentin Wilmart ◽  
Houssein El Dirani ◽  
Nicola Tyler ◽  
Daivid Fowler ◽  
Stéphane Malhouitre ◽  
...  

Silicon photonics is one of the most prominent technology platforms for integrated photonics and can support a wide variety of applications. As we move towards a mature industrial core technology, we present the integration of silicon nitride (SiN) material to extend the capabilities of our silicon photonics platform. Depending on the application being targeted, we have developed several integration strategies for the incorporation of SiN. We present these processes, as well as key components for dedicated applications. In particular, we present the use of SiN for athermal multiplexing in optical transceivers for datacom applications, the nonlinear generation of frequency combs in SiN micro-resonators for ultra-high data rate transmission, spectroscopy or metrology applications and the use of SiN to realize optical phased arrays in the 800–1000 nm wavelength range for Light Detection And Ranging (LIDAR) applications. These functionalities are demonstrated using a 200 mm complementary metal-oxide-semiconductor (CMOS)-compatible pilot line, showing the versatility and scalability of the Si-SiN platform.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Thomas Cole ◽  
Ye Fan ◽  
...  

AbstractThe gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 $$^{\circ }$$ ∘ C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 $$^{\circ }$$ ∘ C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Things.


2021 ◽  
Author(s):  
Daniel Popa ◽  
Richard Hopper ◽  
Syed Zeeshan Ali ◽  
Matthew Cole ◽  
Ye Fan ◽  
...  

Abstract The gas sensor market is growing fast, driven by many socioeconomic and industrial factors. Mid-infrared (MIR) gas sensors offer excellent performance for an increasing number of sensing applications in healthcare, smart homes, and the automotive sector. Having access to low-cost, miniaturized, energy efficient light sources is of critical importance for the monolithic integration of MIR sensors. Here, we present an on-chip broadband thermal MIR source fabricated by combining a complementary metal oxide semiconductor (CMOS) micro-hotplate with a dielectric-encapsulated carbon nanotube (CNT) blackbody layer. The micro-hotplate was used during fabrication as a micro-reactor to facilitate high temperature (>700 • C) growth of the CNT layer and also for post-growth thermal annealing. We demonstrate, for the first time, stable extended operation in air of devices with a dielectric-encapsulated CNT layer at heater temperatures above 600 • C. The demonstrated devices exhibit almost unitary emissivity across the entire MIR spectrum, offering an ideal solution for low-cost, highly-integrated MIR spectroscopy for the Internet of Sensors.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeffrey Schuster ◽  
Johannes Aberl ◽  
Lada Vukušić ◽  
Lukas Spindlberger ◽  
Heiko Groiss ◽  
...  

AbstractThe Si/SiGe heterosystem would be ideally suited for the realization of complementary metal-oxide-semiconductor (CMOS)-compatible integrated light sources, but the indirect band gap, exacerbated by a type-II band offset, makes it challenging to achieve efficient light emission. We address this problem by strain engineering in ordered arrays of vertically close-stacked SiGe quantum dot (QD) pairs. The strain induced by the respective lower QD creates a preferential nucleation site for the upper one and strains the upper QD as well as the Si cap above it. Electrons are confined in the strain pockets in the Si cap, which leads to an enhanced wave function overlap with the heavy holes near the upper QD’s apex. With a thickness of the Si spacer between the stacked QDs below 5 nm, we separated the functions of the two QDs: The role of the lower one is that of a pure stressor, whereas only the upper QD facilitates radiative recombination of QD-bound excitons. We report on the design and strain engineering of the QD pairs via strain-dependent Schrödinger-Poisson simulations, their implementation by molecular beam epitaxy, and a comprehensive study of their structural and optical properties in comparison with those of single-layer SiGe QD arrays. We find that the double QD arrangement shifts the thermal quenching of the photoluminescence signal at higher temperatures. Moreover, detrimental light emission from the QD-related wetting layers is suppressed in the double-QD configuration.


1999 ◽  
Vol 592 ◽  
Author(s):  
Sanjit Singh Dang ◽  
Christos G. Takoudis

ABSTRACTUltra-thin silicon nitride films are being studied for use as high-dielectric constant (highk) materials in future gate dielectric applications, as Complementary Metal-Oxide-Semiconductor (CMOS) transistors are scaled down to the sub-100nm regime. In this study, process modifications are proposed to reduce the total charge and interface trap densities in sub-3.5 nm-thick silicon nitride films, grown in NH3, in a conventional furnace at 900°C and 1 atm. It is shown that by employing a short (<1 min) oxynitridation step in NO, before nitridation, and oxynitridation/Ar-annealing steps, after nitridation, silicon nitride films can be thermally grown with a total charge density as low as about 2.5E10 q/cm2 and an interface trap density of about 2.1E11/(eV-cm2). Besides, the effect of using NO as opposed to N2O for oxynitridation steps is also discussed.


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