Ultra-high amplified strain on 200 mm optical Germanium-On-Insulator (GeOI) substrates: towards CMOS compatible Ge lasers

Currently, one of the main challenges in the field of silicon photonics is the fabrication of efficient laser sources compatible with the microelectronic fabrication technology. An alternative to the complexity of integration of group III-V laser compounds is advancing from high tensile strains applied to germanium leading to improved emission properties by transforming the material from an indirect to a direct bandgap semiconductor. Theory predicts this transformation occurs at around 4.7% uniaxial tensile strain or 2.0% bi-axial tensile strain. Here, we report on ultrahigh strains obtained by amplifying the residual strain from novel optical Germanium-On-Insulator (GeOI) substrates fabricated by Smart CutTM technology and patterned with micro-bridges and micro-crosses. The high crystalline quality of the GeOI layers dramatically declined the mechanical failure limits when liberating the Ge microbridges. Record level Raman shift of 8.1 cm-1 for biaxial (micro-crosses) and 8.7 cm-1 for uniaxial stress (micro-bridges) were reached by carefully designing the geometry of the micro-structures. The photoluminescence (PL) evolution is compared to theoretical calculations based on the tight-binding model revealing a detailed understanding of the influence of strain on the germanium optical properties.

[1]  Emmanuel Augendre,et al.  Challenges and Progress in Germanium-on-Insulator Materials and Device Development towards ULSI Integration , 2009 .

[2]  Jérôme Faist,et al.  Analysis of enhanced light emission from highly strained germanium microbridges , 2013, Nature Photonics.

[3]  Y. Bogumilowicz,et al.  (Invited) SOI-Type Bonded Structures for Advanced Technology Nodes , 2014 .

[4]  O. Kermarrec,et al.  Enhanced photoluminescence of heavily n-doped germanium , 2009 .

[5]  Krishna C. Saraswat,et al.  Roadmap to an Efficient Germanium-on-Silicon Laser: Strain vs. n-Type Doping , 2012, IEEE Photonics Journal.

[6]  Jérôme Faist,et al.  1.9% bi-axial tensile strain in thick germanium suspended membranes fabricated in optical germanium-on-insulator substrates for laser applications , 2015 .

[7]  James S. Harris,et al.  Strong enhancement of direct transition photoluminescence with highly tensile-strained Ge grown by molecular beam epitaxy , 2011 .

[8]  Van de Walle CG.  Band lineups and deformation potentials in the model-solid theory. , 1989, Physical review. B, Condensed matter.

[9]  Jean-Michel Hartmann,et al.  Germanium content and strain in Si1−xGex alloys characterized by Raman spectroscopy , 2014 .

[10]  Krishna C. Saraswat,et al.  Direct bandgap germanium-on-silicon inferred from 5.7% 〈100〉 uniaxial tensile strain [Invited] , 2014 .

[11]  Alban Gassenq,et al.  Structural and optical properties of 200 mm germanium-on-insulator (GeOI) substrates for silicon photonics applications , 2015, Photonics West - Optoelectronic Materials and Devices.

[12]  C. Tavernier,et al.  Onsite matrix elements of the tight-binding Hamiltonian of a strained crystal: Application to silicon, germanium, and their alloys , 2009, 0902.0491.

[13]  Fred H. Pollak,et al.  Stress-Induced Shifts of First-Order Raman Frequencies of Diamond- and Zinc-Blende-Type Semiconductors , 1972 .

[14]  Zoran Ikonic,et al.  Optimum strain configurations for carrier injection in near infrared Ge lasers , 2012 .

[15]  V. Destefanis,et al.  Reduced pressure chemical vapor deposition of Ge thick layers on Si(0 0 1), Si(0 1 1) and Si(1 1 1) , 2008 .

[16]  Van de Walle Cg.  Band lineups and deformation potentials in the model-solid theory. , 1989 .

[17]  K. Bourdelle,et al.  Power-dependent Raman analysis of highly strained Si nanobridges. , 2014, Nano letters.

[18]  Jurgen Michel,et al.  Direct band gap narrowing in highly doped Ge , 2013 .

[19]  Krishna C. Saraswat,et al.  Study of Carrier Statistics in Uniaxially Strained Ge for a Low-Threshold Ge Laser , 2014, IEEE Journal of Selected Topics in Quantum Electronics.

[20]  David A B Miller,et al.  Optical modulator on silicon employing germanium quantum wells. , 2007, Optics express.

[21]  V. Reboud,et al.  Study of the light emission in Ge layers and strained membranes on Si substrates , 2016 .

[22]  J. M. Fedeli,et al.  Structural, electrical and optical properties of in-situ phosphorous-doped Ge layers , 2012 .

[23]  J Gobrecht,et al.  Top-down fabricated silicon nanowires under tensile elastic strain up to 4.5% , 2012, Nature Communications.

[24]  Isabelle Sagnes,et al.  Tensile-strained germanium microdisks , 2013 .

[25]  J. Hartmann,et al.  Germanium avalanche receiver for low power interconnects , 2014, Nature Communications.

[26]  Jean-Michel Hartmann,et al.  Reduced Pressure - Chemical Vapor Deposition of Ge thick layers on Si(001) for microelectronics and optoelectronics purposes , 2004 .

[27]  Frederic Allibert,et al.  Germanium-on-insulator (GeOI) structures realized by the Smart Cut technology , 2004 .