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Laser and Rapid-thermal Crystallization of Low-defect GeSn and SiGeSn Layers for High Performance Infrared Detectors and Integrated Si-based Optoelectronic Devices

Description:

TECHNOLOGY AREA(S): Sensors

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.

OBJECTIVE: Develop low defect laser and rapid thermally crystallized germanium tin (GeSn) and silicon germanium tin (SiGeSn) layers on silicon substrates for mid-wave infrared (MWIR) detectors and integrated Si-based optoelectronic devices.

DESCRIPTION: Conventional mid-infrared materials based on III-V (i.e, gallium indium antimony, or GaInSb) and II-VI (i.e, mercury cadmium tellurium, or HgCdTe) materials are relatively expensive and incompatible with silicon-based integrated circuit processing. Silicon germanium (SiGe) technology is pervasive for electronic applications, but the indirect energy gap prevents extensive applications in optoelectronics. Recent progress on germanium tin (GeSn) and silicon germanium tin (SiGeSn) source materials[1] and the demonstration of a direct energy gap for certain compositions[2] promises significant optical performance, similar to the III-V compounds, but compatible with silicon complementary metal oxide semiconductor (CMOS) device processing. Extremely high quality thin films and initial proof-of-concept emitters and detectors have been demonstrated[3] on Ge substrates, but corresponding films on Si substrates suffer from high defects levels[4] due to the lattice mismatch of high Sn content SiGeSn alloys necessary for direct energy gap devices. Growth of GeSn and SiGeSn emitters and detectors on Si substrates are critical for mass production of large form factor MWIR detectors and integrated optoelectronic devices using standard CMOS production equipment and large-diameter Si wafers.

Recently, it has been shown that excimer laser heating can be used to produce graded low-defect SiGe layers on Si substrates, i.e., a pseudo SiGe substrate[5]. Therefore, it should be feasible to apply excimer laser or rapid thermal crystallization of GeSn or SiGeSn epitaxial layers in order to produce low-defect layers for MWIR detectors and integrated Si-based optoelectronic devices. Ultimately, a process technology could be developed to form low defect SiGeSn pseudo-substrates on Si wafers tailored to specific optoelectronic device applications and wavelengths. Laser crystallization of amorphous Si into polycrystalline Si by explosive crystallization on glass substrates using industrial excimer line lasers is widely used in the display industry for high mobility thin film transistors (TFTs); thus, if successful this technology could be rapidly scaled and industrialized.

PHASE I: Demonstrate low thermal budget excimer laser and rapid thermal crystallization synthesis of GeSn or SiGeSn layers with tin concentrations [Sn]>10% on Si and silicon-on-insulator (SOI) substrates. Demonstrate at least 100x reduction in defect density compared to typical vacuum deposition. Provide experimental evidence for improved optical absorption, IR emission and narrower X-ray rocking curves.

PHASE II: Fabricate and characterize infrared emitters and detectors operating within the spectral range of 2 to 5 um on low-defect crystallized GeSn and SiGeSn layers on Si or SOI substrates. Demonstrate on-wafer integration of photonic and electronic device functionality. Demonstrate at least 2x device performance improvement over corresponding devices formed on layers grown by other techniques where no recrystallization has been performed.

PHASE III DUAL USE APPLICATIONS: Device quality GeSn and SiGeSn films will be used to make infrared (IR) device structures as required by military and commercial customers including those who manufacture integrated circuits and IR optical emitters and detectors.

REFERENCES:

    • J. Kouvetakis and A.V.G. Chizmeshya, “New classes of Si-based photonic Materials and Device Architectures via Designer Molecular Routes,” J. Mater. Chem., v. 17, pp. 1649-1655, 2007.

 

    • Matthew Coppinger, John Hart, Nupur Bhargava, Sangcheol Kim, and James Kolodzey, “Photoconductivity of Germanium Tin Alloys Grown by Molecular Beam Epitaxyâ,” Appl. Phys. Lett. 102, 141101 (2013).

 

    • R. Roucka, J. Mathews, C. Weng, R. Beeler, J. Tolle, J. Menendez, and J. Kouvetakis, “High-Performance Near-IR Photodiodes: A Novel Chemistry-based Approach to Ge and Ge/Sn Devices Integrated on Silicon,” IEEE J. Quantum Electronics, v. 47 (2), pp. 213- 222, Feb. 2011.

 

    • J. Taraci, S. Zollner, M. R. McCartney, J. Menendez, M. A. Santana-Aranda, D. J. Smith, A. Haaland, A.V. Tutukin, G. Gundersen, G. Wolf, and J. Kouvetakis, “Synthesis of Silicon-based Infrared Semiconductors in the Ge-Sn System Using Molecular Chemistry methods,” J. Am. Chem. Soc., v. 123 (44), pp. 10980-10987, 2001.

 

  • C. Y. Ong, K. L. Pey, K. K. Ong, D. X. M. Tan, X. C. Wang, H. Y. Zheng, C. M. Ng,and L. Chan, “A Low-cost Method of Forming Epitaxy SiGe on Si Substrate by Laser Annealing,” Appl. Phys. Lett. 94, 082104 (2009).

KEYWORDS: laser crystallization, rapid thermal annealing, excimer lasers, SiGeSn, SiSn, GeSn, silicon, germanium, silicon-germanium-tin, buffer layers, molecular beam epitaxy, MBE, CVD, chemical vapor deposition, emitters, detectors, Group IV photonics, silicon photonics, optoelectronic devices, device fabrication, growth, heterostructures, radiative recombination, quantum efficiency, semiconductor characterization, superlattices, infrared

  • TPOC-1: Bruce Claflin
  • Phone: 937-528-8740
  • Email: bruce.claflin.1@us.af.mil
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