Exploring SiSn as a performance enhancing semiconductor: A theoretical and experimental approach

Wehbe

Applied Physics Letters

2015

Self Cite

We report a theoretical analysis and experimental verification of change in band gap of silicon lattice due to the incorporation of tin (Sn). We formed SiSn ultra-thin film on the top surface of a 4 in. silicon wafer using thermal diffusion of Sn. We report a reduction of 0.1 V in the average built-in potential, and a reduction of 0.2 V in the average reverse bias breakdown voltage, as measured across the substrate. These reductions indicate that the band gap of the silicon lattice has been reduced due to the incorporation of Sn, as expected from the theoretical analysis. We report the experimentally calculated band gap of SiSn to be 1.11 ± 0.09 eV. This low-cost, CMOS compatible, and scalable process offers a unique opportunity to tune the band gap of silicon for specific applications.

mentioning

confidence: 59%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

SiSn diodes: Theoretical analysis and experimental verification

Wehbe

Applied Physics Letters

2015

Self Cite

Physica Status Solidi (b)

“…The bandgap of Si 1-x Sn x , tuned by manipulating the Sn atomic concentration, [26] allowed researchers to alter the compound's characteristics to suit their device applications. Consequently, they have been utilized in the fabrication of p-MOSFETs, [27] MuGFETs, [26] MOSCAPs, [28] diodes, [29] low standby power (LSTP) devices, [30] and photovoltaic devices. [31] Due to their optical and electrical properties, Si 1-x Sn x alloys have emerged as promising candidates for temperature sensing materials.…”

Section: Introductionmentioning

confidence: 99%

Amorphous SiSn Alloy: Another Candidate Material for Temperature Sensing Layers in Uncooled Microbolometers

ElGhonimy

Abdel‐Rahman

Hezam

et al. 2021

Herein, the prospect of using amorphous Si1–x Sn x alloys as alternative temperature‐sensing active materials in microbolometers is evaluated by studying their temperature‐dependent resistive properties along with their infrared optical properties. Si1–x Sn x thin films (200 nm thick), with varying Sn concentrations, are prepared at room temperature by cosputtering from Si and Sn targets using simultaneous radio frequency and DC magnetron sputter deposition. Low beam energy X‐ray microanalysis is used to estimate the atomic concentrations of the prepared films. Atomic force microscopy analysis shows an increase in the root‐mean‐square surface roughness of the prepared Si1–x Sn x thin films, with increasing Sn content. Sheet resistance versus temperature measurements are performed yielding temperature coefficients of resistance of 3.25, 2.65, and 1.72% K−1 at resistivity values of 116.18, 27.36, and 2.34 Ω cm for Sn concentrations of 35%, 44%, and 48%, respectively. Infrared ellipsometry measurements are performed to extract the optical properties of the Si1–x Sn x thin films and optical simulations confirm that a Fabry–Pérot cavity microbolometer configuration containing an Si1–x Sn x thin film can achieve high absorptance in the 8–12 μm band. This study shows that Si1–x Sn x alloys are a suitable, simple, and low‐cost replacement for thermometer layers used in uncooled infrared microbolometers.

J. Phys. D: Appl. Phys.

“…Among group IV alloys such conditions may be present in many systems but the electronic band structure has not been extensively analyzed. Just a handful of published theoretical and experimental papers only for selected systems [27][28][29][30][31][32][33][34][35][36][37][38][39] and no cross-sectional work can be found for such alloys. A systematic study and comparison of the group IV alloys would provide a valuable insight into the chemical trends, which this paper aims to provide and which have not been studied previously.…”

Section: Introductionmentioning

confidence: 99%

The effect of isovalent doping on the electronic band structure of group IV semiconductors

Polak¹,

Scharoch²,

Kudrawiec³

2020

The band gap engineering of group IV semiconductors has not been well explored theoretically and experimentally, except for SiGe. Recently, GeSn has attracted much attention due to the possibility of obtaining a direct band gap in this alloy, thereby making it suitable for light emitters. Other group IV alloys may also potentially exhibit material properties useful for device applications, expanding the space for band gap engineering in group IV. In this work the electronic band structure of all group IV semiconductor alloys is investigated. Twelve possible A:B alloys, where A is a semiconducting host (A = C, Si, and Ge) and B is an isovalent dopant (B = C, Si, Ge, Sn, and Pb), were studied in the dilute regime (0.8%) of the isovalent dopant in the entire Brillouin zone (BZ), and the chemical trends in the evolution of their electronic band structure were carefully analyzed. Density functional theory with state-of-the-art methods such as meta-GGA functionals and a spectral weight approach to band unfolding from large supercells was used to obtain dopant-related changes in the band structure, in particular the direct band gap at the Γ point and indirect band gaps at the L(X) points of the BZ. Analysis of contributions from geometry distortion and electronic interaction was also performed. Moreover, the obtained results are discussed in the context of obtaining a direct fundamental gap in Ge:B (B = C, Sn, and Pb) alloys, and intermediate band formation in C:B (B = Sn and Pb) and Ge:C. An increase in localization effects is also observed: a strong hole localization for alloys diluted with a dopant of a larger covalent radius and a strong electron localization for alloys with a dopant of smaller radius. Finally, it is shown that alloying Si and Ge with other elements from group IV is a promising way to enhance the functionality of group IV semiconductors.