Séminaire IM2NP - Abderraouf Boucherif - Jeudi 25 juin à 11h
Salle des séminaires de l'Im2np, campus de Saint-Jérôme, 1er étage Bâtiment Poincaré
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Invitation : Mathieu ABEL (Département EMONA, Equipe NOVA)
Diffusion : IM2NP, CINaM, Irphe, Madirel, LP3, PIIM, CPT, Fédération de Chimie, CP2M
Abderraouf Boucherif
Laboratoire 3IT - Université de Sherbrooke, Sherbrooke, Canada
Freestanding Semiconductor Membranes for Optoelectronics
Freestanding semiconductor membranes (FSMs) have recently emerged as a highly promising platform for next-generation optoelectronic and photovoltaic technologies [1]. In this contribution, I will review recent advances in FSM technologies, with emphasis on their potential for lightweight, flexible, and stackable device architectures, as well as their capacity to enable the heterogeneous integration of high-performance III–V materials with silicon-based platforms. Various approaches for membrane fabrication, epitaxial lift-off, and integration will be discussed, highlighting their respective advantages, limitations, and prospects for scalability.
Among these approaches, particular attention will be given to Porous Lift-Off, an emerging strategy that employs nanoengineered porous semiconductor layers as sacrificial release layers for the fabrication of freestanding monocrystalline membranes. Compared with conventional lift-off techniques, porous lift-off offers several advantages, including compatibility with large-area processing, preservation of crystal quality, reduced material consumption, and the possibility of substrate reuse. Different porous lift-off approaches developed on silicon, germanium, and III–V materials will be reviewed and compared.
In this context, I will present recent progress achieved by our team using porous germanium release layers to fabricate wafer-scale freestanding germanium nanomembranes [2]. Through the engineering of a porous Ge sacrificial layer, monocrystalline Ge membranes exhibiting sub-nanometer surface roughness (≤ 1 nm) and excellent crystalline quality have been demonstrated at the wafer scale. These membranes are fully compatible with subsequent III–V epitaxy, enabling the fabrication of high-performance GaAs solar cells [4]. A key advantage of this approach is the demonstrated ability to recondition and reuse the parent Ge wafer over multiple growth and release cycles, substantially reducing material consumption and enabling a more sustainable semiconductor manufacturing pathway [3]. As a proof of concept, photovoltaic devices fabricated on released Ge membranes have demonstrated device-grade performance, confirming the practical viability of this technology [2], [4].
Another approach that will be reviewed and discussed is Anchor Point Nucleation (APN), a graphene-enabled epitaxial strategy developed to overcome fundamental limitations of remote epitaxy. By introducing controlled defects into the graphene layer—such as dangling bonds and nanoholes—preferential nucleation sites are generated, enabling the growth of high-quality single-crystalline semiconductor layers. Unlike conventional remote epitaxy, APN enables the epitaxial growth of both polar and non-polar materials on graphene-coated substrates. Structural analyses have demonstrated the formation of defect-free, stress-free monocrystalline layers aligned with the underlying substrate, establishing APN as a versatile route toward universal 3D/2D heterointegration [5].
Overall, this work will provide a comprehensive perspective on emerging strategies for FSM fabrication and heteroepitaxy, positioning Porous Lift-Off and APN as complementary and promising routes toward scalable, sustainable, and high-performance semiconductor platforms for advanced optoelectronic applications.
Among these approaches, particular attention will be given to Porous Lift-Off, an emerging strategy that employs nanoengineered porous semiconductor layers as sacrificial release layers for the fabrication of freestanding monocrystalline membranes. Compared with conventional lift-off techniques, porous lift-off offers several advantages, including compatibility with large-area processing, preservation of crystal quality, reduced material consumption, and the possibility of substrate reuse. Different porous lift-off approaches developed on silicon, germanium, and III–V materials will be reviewed and compared.
In this context, I will present recent progress achieved by our team using porous germanium release layers to fabricate wafer-scale freestanding germanium nanomembranes [2]. Through the engineering of a porous Ge sacrificial layer, monocrystalline Ge membranes exhibiting sub-nanometer surface roughness (≤ 1 nm) and excellent crystalline quality have been demonstrated at the wafer scale. These membranes are fully compatible with subsequent III–V epitaxy, enabling the fabrication of high-performance GaAs solar cells [4]. A key advantage of this approach is the demonstrated ability to recondition and reuse the parent Ge wafer over multiple growth and release cycles, substantially reducing material consumption and enabling a more sustainable semiconductor manufacturing pathway [3]. As a proof of concept, photovoltaic devices fabricated on released Ge membranes have demonstrated device-grade performance, confirming the practical viability of this technology [2], [4].
Another approach that will be reviewed and discussed is Anchor Point Nucleation (APN), a graphene-enabled epitaxial strategy developed to overcome fundamental limitations of remote epitaxy. By introducing controlled defects into the graphene layer—such as dangling bonds and nanoholes—preferential nucleation sites are generated, enabling the growth of high-quality single-crystalline semiconductor layers. Unlike conventional remote epitaxy, APN enables the epitaxial growth of both polar and non-polar materials on graphene-coated substrates. Structural analyses have demonstrated the formation of defect-free, stress-free monocrystalline layers aligned with the underlying substrate, establishing APN as a versatile route toward universal 3D/2D heterointegration [5].
Overall, this work will provide a comprehensive perspective on emerging strategies for FSM fabrication and heteroepitaxy, positioning Porous Lift-Off and APN as complementary and promising routes toward scalable, sustainable, and high-performance semiconductor platforms for advanced optoelectronic applications.
References
[1] H. Kim et al., “Remote epitaxy,” Nat. Rev. Methods Primer, vol. 2, no. 1, p. 40, 2022.
[2] N. Paupy et al., “Wafer-scale detachable monocrystalline germanium nanomembranes for the growth of III–V materials and substrate reuse,” Nanoscale Advances, vol. 5, pp. 4696–4702, 2023.
[3] A. Chapotot et al., “Sequential fabrication of multiple Ge nanomembranes from a single wafer: Towards sustainable recycling of Ge substrates,” Sustainable Materials and Technologies, vol. 39, e00806, 2024.
[4] V. Daniel et al., “High-Efficiency GaAs Solar Cells Grown on Porous Germanium Substrate with PEELER Technology,” Solar RRL, vol. 8, no. 1, 2024.
[5] T. M. Diallo et al., “Unraveling the Heterointegration of 3D Semiconductors on Graphene by Anchor Point Nucleation,” Small, vol. 20, no. 15, 2306038, 2024.
[1] H. Kim et al., “Remote epitaxy,” Nat. Rev. Methods Primer, vol. 2, no. 1, p. 40, 2022.
[2] N. Paupy et al., “Wafer-scale detachable monocrystalline germanium nanomembranes for the growth of III–V materials and substrate reuse,” Nanoscale Advances, vol. 5, pp. 4696–4702, 2023.
[3] A. Chapotot et al., “Sequential fabrication of multiple Ge nanomembranes from a single wafer: Towards sustainable recycling of Ge substrates,” Sustainable Materials and Technologies, vol. 39, e00806, 2024.
[4] V. Daniel et al., “High-Efficiency GaAs Solar Cells Grown on Porous Germanium Substrate with PEELER Technology,” Solar RRL, vol. 8, no. 1, 2024.
[5] T. M. Diallo et al., “Unraveling the Heterointegration of 3D Semiconductors on Graphene by Anchor Point Nucleation,” Small, vol. 20, no. 15, 2306038, 2024.
