Chemistry:Germanium-tin
Germanium-tin is an alloy of the elements germanium and tin, both located in group 14 of the periodic table. It is only thermodynamically stable under a small composition range. Despite this limitation, it has useful properties for band gap and strain engineering of silicon-integrated optoelectronic and microelectronic semiconductor devices.
Synthesis
Germanium-tin alloys must be kinetically stabilized in order to prevent decomposition.[1][2] Therefore, low temperature molecular beam epitaxy or chemical vapor deposition techniques are typically used for their synthesis.[1]
Microelectronic applications
Germanium-tin alloys have higher carrier mobilities than either silicon or germanium. Therefore it has been proposed that they can be used as a channel material in high speed metal-oxide-semiconductor field effect transistors.[3] In addition, the alloys' larger lattice constant relative to germanium makes it possible to use them as stressors to enhance the carrier mobility of germanium channel transistors.[3][4]
Optoelectronic applications
At a Sn content beyond approximately 9%, germanium-tin alloys become direct gap semiconductors having efficient light emission suitable for the fabrication of lasers.[5] Since the constituent elements are chemically compatible with silicon, it is possible to integrate such lasers directly onto silicon microelectronic devices, enabling on-chip optical communication. This is still an active research area, but germanium-tin lasers operating at low temperatures have already been demonstrated.[6][7] In addition, germanium-tin light emitting diodes operating at room temperature have also been reported.[8][9]
References
- ↑ 1.0 1.1 Wirths, S.; Buca, D.; Mantl, S. (2016). "Si–Ge–Sn alloys: From growth to applications". Progress in Crystal Growth and Characterization of Materials (Elsevier BV) 62 (1): 1–39. doi:10.1016/j.pcrysgrow.2015.11.001. ISSN 0960-8974.
- ↑ Kouvetakis, J.; Menendez, J.; Chizmeshya, A.V.G. (2006). "Tin-Based Group IV Semiconductors: New Platforms for Opto- and Microelectronics on Silicon". Annual Review of Materials Research (Annual Reviews) 36 (1): 497–554. doi:10.1146/annurev.matsci.36.090804.095159. ISSN 1531-7331.
- ↑ 3.0 3.1 Loo, R.; Vincent, B.; Gencarelli, F.; Merckling, C.; Kumar, A. et al. (2012-12-07). "Ge1−xSnx Materials: Challenges and Applications". ECS Journal of Solid State Science and Technology (The Electrochemical Society) 2 (1): N35–N40. doi:10.1149/2.039301jss. ISSN 2162-8769.
- ↑ Vincent, B.; Shimura, Y.; Takeuchi, S.; Nishimura, T.; Eneman, G. et al. (2011). "Characterization of GeSn materials for future Ge pMOSFETs source/drain stressors". Microelectronic Engineering (Elsevier BV) 88 (4): 342–346. doi:10.1016/j.mee.2010.10.025. ISSN 0167-9317.
- ↑ Gallagher, J. D.; Senaratne, C. L.; Kouvetakis, J.; Menéndez, J. (2014-10-06). "Compositional dependence of the bowing parameter for the direct and indirect band gaps in Ge1−ySny alloys". Applied Physics Letters (AIP Publishing) 105 (14): 142102. doi:10.1063/1.4897272. ISSN 0003-6951.
- ↑ "Scientists construct the first germanium-tin semiconductor laser for silicon chips". Phys.org. 2015-01-20. http://phys.org/news/2015-01-scientists-germanium-tin-semiconductor-laser-silicon.html. Retrieved 2019-12-12.
- ↑ Prachi Patel (2015-01-22). "The Germanium-Tin Laser: Answer to the On-Chip Data Bottleneck?". IEEE Spectrum. https://spectrum.ieee.org/tech-talk/semiconductors/optoelectronics/germaniumtin-laser-for-optical-interconnects. Retrieved 2019-12-12.
- ↑ Gallagher, J. D.; Senaratne, C. L.; Sims, P.; Aoki, T.; Menéndez, J.; Kouvetakis, J. (2015-03-02). "Electroluminescence from GeSn heterostructure pin diodes at the indirect to direct transition". Applied Physics Letters (AIP Publishing) 106 (9): 091103. doi:10.1063/1.4913688. ISSN 0003-6951.
- ↑ Senaratne, C. L.; Wallace, P. M.; Gallagher, J. D.; Sims, P. E.; Kouvetakis, J.; Menéndez, J. (2016-07-14). "Direct gap Ge1−ySny alloys: Fabrication and design of mid-IR photodiodes". Journal of Applied Physics (AIP Publishing) 120 (2): 025701. doi:10.1063/1.4956439. ISSN 0021-8979.
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