Academic and industry research progress in germanium nanodevices
TL;DR: Germanium-based transistors have the potential to operate at high speeds with low power requirements and might therefore be used in non-silicon-based semiconductor technology in the future.
Abstract: Silicon has enabled the rise of the semiconductor electronics industry, but it was not the first material used in such devices. During the 1950s, just after the birth of the transistor, solid-state devices were almost exclusively manufactured from germanium. Today, one of the key ways to improve transistor performance is to increase charge-carrier mobility within the device channel. Motivated by this, the solid-state device research community is returning to investigating the high-mobility material germanium. Germanium-based transistors have the potential to operate at high speeds with low power requirements and might therefore be used in non-silicon-based semiconductor technology in the future.
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01 May 2019
TL;DR: In this paper, a review of the physical properties of the group IV monochalcogenides of 2D and layered materials is presented, highlighting new electronic and photonic device concepts and novel physical phenomena and discuss future directions.
Abstract: The family of 2D and layered materials has been expanding rapidly for more than a decade. Within this large family of hundreds of materials, black phosphorus and its isoelectronic group IV monochalcogenides have a unique place. These puckered materials have distinctive crystalline symmetries and exhibit various exciting properties, such as high carrier mobility, strong infrared responsivity, widely tunable bandgap, in-plane anisotropy and spontaneous electric polarization. Here, we review their basic properties, highlight new electronic and photonic device concepts and novel physical phenomena and discuss future directions. Layered black phosphorus and its isoelectronic group IV monochalcogenides have distinctive physical properties arising from their unusual crystal symmetries. This Review discusses some of the interesting physical phenomena, possible device applications and future research directions for this group of materials.
179 citations
TL;DR: In the effort to develop disruptive quantum technologies, germanium is emerging as a versatile material to realize devices capable of encoding, processing and transmitting quantum information as mentioned in this paper, such as a universal quantum gate set with spin qubits in quantum dots and superconductor-semiconductor hybrid quantum systems.
Abstract: In the effort to develop disruptive quantum technologies, germanium is emerging as a versatile material to realize devices capable of encoding, processing and transmitting quantum information. These devices leverage the special properties of holes in germanium, such as their inherently strong spin–orbit coupling and their ability to host superconducting pairing correlations. In this Review, we start by introducing the physics of holes in low-dimensional germanium structures, providing key insights from a theoretical perspective. We then examine the materials-science progress underpinning germanium-based planar heterostructures and nanowires. We go on to review the most significant experimental results demonstrating key building blocks for quantum technology, such as an electrically driven universal quantum gate set with spin qubits in quantum dots and superconductor–semiconductor devices for hybrid quantum systems. We conclude by identifying the most promising avenues towards scalable quantum information processing in germanium-based systems. Germanium is a promising material to build quantum components for scalable quantum information processing. This Review examines progress in materials science and devices that has enabled key building blocks for germanium quantum technology, such as hole-spin qubits and superconductor–semiconductor hybrids.
150 citations
TL;DR: This Review Article highlights the progress that has been made and insights into the strategies used for the colloidal synthesis of size and shape-controlled germanium nanomaterials and surveys some of the potential applications of these materials in optoelectronics, biological imaging, and energy conversion and storage.
Abstract: Germanium nanoparticles have excited scientists and engineers because of their size-dependent optical properties and their potential applications in optoelectronics, biological imaging and therapeutics, flash memories, and lithium-ion batteries. In order to further develop these applications and to gain deeper insights into their size-dependent properties, robust and facile synthetic methods are needed to controllably synthesize Ge nanoparticles. However, when compared to other II–VI, IV–VI, and III–V semiconductor systems, colloidal routes to Ge NPs with uniform sizes and shapes are much less mature. In this Review Article, we highlight the progress that has been made in this field and provide insights into the strategies used for the colloidal synthesis of size and shape-controlled germanium nanomaterials. We also survey some of the potential applications of these materials in optoelectronics, biological imaging, and energy conversion and storage. Finally, we discuss the colloidal synthesis of other germanium-containing compounds, emphasizing technologically relevant germanium chalcogenides that include GeS, GeSe, and GeTe.
148 citations
TL;DR: This work reviews the two major remaining challenges that Ge based devices must overcome if they are to replace Si as the channel material, namely, heterogeneous integration of Ge on Si substrates, and developing a suitable gate stack.
Abstract: The performance of strained silicon (Si) as the channel material for today's metal-oxide-semiconductor field-effect transistors may be reaching a plateau. New channel materials with high carrier mobility are being investigated as alternatives and have the potential to unlock an era of ultra-low-power and high-speed microelectronic devices. Chief among these new materials is germanium (Ge). This work reviews the two major remaining challenges that Ge based devices must overcome if they are to replace Si as the channel material, namely, heterogeneous integration of Ge on Si substrates, and developing a suitable gate stack. Next, Ge is compared to compound III-V materials in terms of p-channel device performance to review how it became the first choice for PMOS devices. Different Ge device architectures, including surface channel and quantum well configurations, are reviewed. Finally, state-of-the-art Ge device results and future prospects are also discussed.
128 citations
Cites background from "Academic and industry research prog..."
...Due to the exceptionally high μh of Ge, and the progress made in Ge based p-channel MOSFETs (pMOSFETs) [6–14] and p-channel quantum well FETs (pQWFETs) [2,15–19] over the last decade, there appears to be a consensus in the device research community and in industry that Ge offers the best option for PMOS devices [1,2,20]....
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...The motivation to replace strained silicon (Si) with higher mobility channel materials in today’s metal-oxide-semiconductor field-effect transistors (MOSFETs) is well documented [1,2]....
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TL;DR: In this article, the physics of holes in low-dimensional germanium structures with key insights from a theoretical perspective are introduced and a review of the most significant experimental results demonstrating key building blocks for quantum technology, such as an electrically driven universal quantum gate set with spin qubits in quantum dots and superconducting pairing correlations.
Abstract: In the worldwide endeavor for disruptive quantum technologies, germanium is emerging as a versatile material to realize devices capable of encoding, processing, or transmitting quantum information. These devices leverage special properties of the germanium valence-band states, commonly known as holes, such as their inherently strong spin-orbit coupling and the ability to host superconducting pairing correlations. In this Review, we initially introduce the physics of holes in low-dimensional germanium structures with key insights from a theoretical perspective. We then examine the material science progress underpinning germanium-based planar heterostructures and nanowires. We review the most significant experimental results demonstrating key building blocks for quantum technology, such as an electrically driven universal quantum gate set with spin qubits in quantum dots and superconductor-semiconductor devices for hybrid quantum systems. We conclude by identifying the most promising prospects toward scalable quantum information processing.
121 citations
References
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01 Dec 2007
TL;DR: In this paper, a 45 nm logic technology is described that for the first time incorporates high-k + metal gate transistors in a high volume manufacturing process, resulting in the highest drive currents yet reported for NMOS and PMOS.
Abstract: A 45 nm logic technology is described that for the first time incorporates high-k + metal gate transistors in a high volume manufacturing process. The transistors feature 1.0 nm EOT high-k gate dielectric, dual band edge workfunction metal gates and third generation strained silicon, resulting in the highest drive currents yet reported for NMOS and PMOS. The technology also features trench contact based local routing, 9 layers of copper interconnect with low-k ILD, low cost 193 nm dry patterning, and 100% Pb-free packaging. Process yield, performance and reliability are demonstrated on 153 Mb SRAM arrays with SRAM cell size of 0.346 mum2, and on multiple microprocessors.
973 citations
08 Dec 2003
TL;DR: In this article, the authors describe a novel strained transistor architecture which is incorporated into a 90nm logic technology on 300mm wafers, which features an epitaxially grown strained SiGe film embedded in the source drain regions.
Abstract: This paper describes the details of a novel strained transistor architecture which is incorporated into a 90nm logic technology on 300mm wafers The unique strained PMOS transistor structure features an epitaxially grown strained SiGe film embedded in the source drain regions Dramatic performance enhancement relative to unstrained devices are reported These transistors have gate length of 45nm and 50nm for NMOS and PMOS respectively, 12nm physical gate oxide and Ni salicide World record PMOS drive currents of 700/spl mu/A//spl mu/m (high V/sub T/) and 800/spl mu/A//spl mu/m (low V/sub T/) at 12V are demonstrated NMOS devices exercise a highly tensile silicon nitride capping layer to induce tensile strain in the NMOS channel region High NMOS drive currents of 126mA//spl mu/m (high VT) and 145mA//spl mu/m (low VT) at 12V are reported The technology is mature and is being ramped into high volume manufacturing to fabricate next generation Pentium/spl reg/ and Intel/spl reg/ Centrino/spl trade/ processor families
729 citations
TL;DR: In this paper, a method of controlling threading dislocation densities in Ge on Si involving graded SiGe layers and chemical-mechanical polishing (CMP) is presented.
Abstract: A method of controlling threading dislocation densities in Ge on Si involving graded SiGe layers and chemical-mechanical polishing (CMP) is presented. This method has allowed us to grow a relaxed graded buffer to 100% Ge without the increase in threading dislocation density normally observed in thick graded structures. This sample has been characterized by transmission electron microscopy, etch-pit density, atomic force microscopy, Nomarski optical microscopy, and triple-axis x-ray diffraction. Compared to other relaxed graded buffers in which CMP was not implemented, this sample exhibits improvements in threading dislocation density and surface roughness. We have also made process modifications in order to eliminate particles due to gas-phase nucleation and cracks due to thermal mismatch strain. We have achieved relaxed Ge on Si with a threading dislocation density of 2.1×106 cm−2, and we expect that further process refinements will lead to lower threading dislocation densities on the order of bulk Ge su...
620 citations
TL;DR: In this article, the opportunities and challenges of high-k/Ge MOSFETs are discussed on the basis of the material properties of Ge oxide to provide insights for future progress.
443 citations