Journal: Materials Science in Semiconductor Processing

Abbreviation

Mater. sci. semicond. process.

Publisher

Elsevier

Journal Volumes

ISSN

1369-8001

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2019 - 201932020 - 20266
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Publications 1 - 9 of 9
  • Control and tuning of color centers in 4H silicon carbide by application of electric field via Schottky diode
    Item type: Journal Article
    Ousdal , Erlend Lemva; Etzelmüller Bathen , Marianne; de Medeiros , Helton Goncalves; et al. (2026)
    Materials Science in Semiconductor Processing
    The ability to tune and manipulate the energy and intensity of photons emitted from color centers in semiconductors is of great importance for developing point defect quantum emitters as a platform for future quantum technology (QT) applications. One of the promising materials to realize point defect based QT is silicon carbide (SiC), as it combines a plethora of color center candidates with mature material processing and device fabrication. Here we explore the use of a Schottky diode, fabricated on a highly doped n-type 4H-SiC epitaxial layer, to control and modulate defect-related emission under both forward and reverse bias conditions. Zero phonon lines (ZPLs) from three prominent color centers are investigated: V1, V1’ and V2 assigned to the silicon vacancy, B1 and B2 from the carbon antisite-vacancy pair, and PL4 of the divacancy complex. All the studied defect-related emission wavelengths are found to shift in response to applied bias, but with a varying magnitude and direction of the shift. The electric field-induced variations are assigned to Stark effect and current flow within the device. Furthermore, two unknown defect signatures, labeled K1 and K2, are observed in the vicinity (within 2 meV) of the V2 ZPL and exhibit a strong forward bias dependence. A possible origin related to silicon vacancies perturbed by nearby carbon antisites is discussed.
  • Dual configuration of shallow acceptor levels in 4H-SiC
    Item type: Journal Article
    Bathen, Marianne; Kumar, Piyush; Ghezellou, Misagh; et al. (2024)
    Materials Science in Semiconductor Processing
    Acceptor dopants in 4H-SiC exhibit energy levels that are located deeper in the band gap than the thermal energy at room temperature (RT), resulting in incomplete ionization at RT. Therefore, a comprehensive understanding of the defect energetics and how the impurities are introduced into the material is imperative. Herein, we study impurity related defect levels in 4H-SiC epitaxial layers (epi-layers) grown by chemical vapor deposition (CVD) under various conditions using minority carrier transient spectroscopy (MCTS). We find two trap levels assigned to boron impurities, B and D, which are introduced to varying degrees depending on the growth conditions. A second acceptor level that was labeled X in the literature and attributed to impurity related defects is also observed. Importantly, both the B and X levels exhibit fine structure revealed by MCTS measurements. We attribute the fine structure to acceptor impurities at hexagonal and pseudo-cubic lattice sites in 4H-SiC, and tentatively assign the X peak to Al based on experimental findings and density functional theory calculations.
  • Material processing of optical devices and their applications
    Item type: Journal Issue
    (2019)
    Materials Science in Semiconductor Processing
  • Al-implantation induced damage in 4H-SiC
    Item type: Journal Article
    Kumar, Piyush; Martins, Maria Inês Mendes; Prokscha, Thomas; et al. (2024)
    Materials Science in Semiconductor Processing
    Ion implantation of 4H-SiC is one of the crucial steps in the fabrication of power devices. This process results in the generation of electrically active defects both in the implanted region and beyond. In this work, we explore the defects created during Al-ion implantation and post implantation annealing using low-energy muon spin rotation (LE-𝜇SR) spectroscopy and deep level transient spectroscopy (DLTS). Two sets of samples, exposed to low fluence (LF) and high fluence (HF) of Al, are examined with and without annealing. The results reveal that defects induced by Al implantation extend deep into the semiconductor, far beyond the implanted region, thus influencing the electrical properties of SiC material. The LF samples exhibit a LE-𝜇SR signature that points to a carbon vacancy (𝑉𝒸) concentration in the range of 1 × 10¹⁵ to 1 × 10¹⁹ cm⁻³. Further, DLTS measurements reveal defect levels associated with silicon vacancies (𝑉ₛᵢ) and carbon vacancies (𝑉𝒸) several μm away from the intended implantation region, indicating that Al implantation and subsequent high-temperature annealing impacts the SiC lattice in a substantial volume. The present study provides valuable insights into the near- surface and bulk effects of Al implantation in 4H-SiC, which is essential for optimizing semiconductor device performance in power electronics applications.
  • Impact of carbon injection in 4H-SiC on defect formation and minority carrier lifetime
    Item type: Journal Article
    Bathen, Marianne; Karsthof, Robert; Galeckas, Augustinas; et al. (2024)
    Materials Science in Semiconductor Processing
    Point defects in silicon carbide (SiC) can act as charge carrier traps and have a pronounced impact on material properties such as the mobility and carrier lifetime. Prominent among these traps is the carbon vacancy (VC) with a demonstrated detrimental effect on the minority carrier lifetime in 4H-SiC epitaxial layers. Hence, a variety of methods for VC removal have been proposed. Common to all is that they involve some sort of C-injection into the epi-layer that leads to annihilation of VC with C interstitials (Ci) via the reaction Ci＋ VC →0̸. However, many studies on injection of Ci for removal of VC do not take into account the potential effect of any additional defects that are formed as a result of excess C in the material, including electrically active defects that introduce energy levels in the SiC band gap. Herein, we study the formation and impact of carbon related defects that are introduced in 4H-SiC epi-layers by injection of excess carbon. C-injection is achieved by annealing 4H-SiC epi-layers covered by a graphitized photoresist known as a C-cap at 1250 °C for different durations. The resulting appearance of defects in the samples is monitored using deep level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS) measurements, which reveal the formation of both minority and majority carrier traps as a result of the C-injection. Intriguingly, the injected carbon is also found to interact with a perennially present impurity in 4H-SiC epi-layers and a potentially lifetime limiting defect, namely boron. Furthermore, we monitor the minority carrier lifetime as a function of C-injection time and depth from the surface using cross-sectional time-resolved photoluminescence (TRPL) measurements. Both the defect distributions and the minority carrier lifetime are found to depend strongly on the duration of the C-cap anneal, with a marked depth dependence being present for all samples studied. The moderate temperature C-cap annealing treatment is proposed as a method for enhancing the carrier lifetime in n-type 4H-SiC epi-layers for power device applications.
  • Editorial. Material Science in Semiconductor Processing: Special Issue: Material processing of optical devices and their applications
    Item type: Other Journal Item
    Romano, Lucia; Vila-Comamala, Joan (2019)
    Materials Science in Semiconductor Processing
  • Fabrication of Au gratings by seedless electroplating for X-ray grating interferometry
    Item type: Journal Article
    Kagias, Matias; Wang, Zhentian; Guzenko, Vitaliy A.; et al. (2019)
    Materials Science in Semiconductor Processing
  • Deep-reactive-ion-etching in X-ray grating fabrication: a review
    Item type: Review Article
    Shi, Zhitian; Jefimovs, Konstantins; Vila-Comamala, Joan; et al. (2026)
    Materials Science in Semiconductor Processing
    The development of grating fabrication shares its journey with the development of X-ray phase contrast imaging. Indeed, the fabrication of gratings with features of sufficiently high aspect ratio is one of the bottlenecks preventing the widespread application of phase contrast imaging in X-ray diagnostics, material science and security. The silicon platform that underlies modern manufacture of integrated circuits, with its well-established technologies for lithography, etching and metal deposition, has the potential to provide high yields and volumes for industrial fabrication of both phase and absorption gratings used in a grating-based X-ray imaging systems. This review article introduces recent developments in the fabrication of high aspect ratio X-ray gratings using ubiquitous clean-room manufacturing tools, focusing on deep reactive ion etching processes. It summarizes the most challenging issues for fabricating features with aspect ratios reaching 70:1, proposing approaches to overcome processing problems and improve product quality. 2025 Elsevier B.V., All rights reserved.
  • Aluminum channeling in 4H-SiC by high-energy implantation above 10 MeV
    Item type: Journal Article
    Belanche Guadas, Manuel; Yonezawa, Yoshiyuki; Heller, René; et al. (2024)
    Materials Science in Semiconductor Processing
    This study explores high-energy aluminum (Al) implantation above 10 MeV as a fabrication process to facilitate the creation of deep doping regions in silicon carbide (SiC). Experimental investigations were conducted to evaluate the technical feasibility of ultra-high energy implantation and high-energy channeling implantation of aluminum into 4H-SiC. Ultra-high-energy Al implantations at 30 and 48 MeV were performed, revealing limitations such as increased charge dispersion and decreased current near accelerator technical limits. In contrast, high-energy channeling implantations at 12, 15, and 20 MeV demonstrated successful Al channeling implantations into 4H-SiC, emphasizing the importance of precision in crystal orientation and mounting systems. Results indicate that channeling implantations, with precise instrumentation, are a preferred approach over non-channeled ultra-high-energy methods for fabricating deep doping regions in SiC, holding promise for advancing the next generation of high-voltage SiC devices.
Publications 1 - 9 of 9