Abstract
Aims: To activate Si and SiGe surfaces by employing the sonochemical treatment at different operating frequencies in dichloromethane to improve the surface photovoltage signal.
Background: To produce integrated electronic devices, one needs to achieve low surface and interface trap densities. In this respect, placing a passivating thin layer on Si and Ge surfaces, which saturates the electronic levels of traps and therefore affects the carrier recombination velocities at the surface, is of great interest.
Objective: Demonstrating the effectiveness of the treatment of Si and SiGe surfaces depends on the ultrasonic frequency used.
Methods: Photovoltaic transients, electron microscopy, EDX spectroscopy.
Results: The surface photovoltage (SPV) decay curves can be divided into rapid (τ1) and slow (τ2) components. The sonication effect on the SPV is different for the treatment done at about 25 and 400 kHz. The SPV signal in Si gradually increases with increasing lower-frequency sonication time, whereas the SPV enhancement on SiGe is somewhat smaller. Increasing the sonication time increases the amplitude of the τ2 component in Si. In SiGe, the lower-frequency sonication quenches the τ2 component yielding a nearly single-exponential decay form. This trend is even more pronounced at the higher-frequency sonication.
Conclusion: The sonochemical treatments greatly intensify the formation of CxHy–Si, and CxHy– Ge bonds on Si and Si1-xGex surfaces, resulting in increased SPV signals and prolonged SPV decay times. These results demonstrate that sonochemical treatment is a more effective technique to obtain stable highly passivated Si and Si1-xGex surfaces in comparison with wet chemical treatments in hydrocarbon solutions.
Keywords: Silicon, germanium, surface passivation, dichloromethane, sonochemical, surface photovoltage, free carrier lifetime, ultrasonic frequency.
Graphical Abstract
[1]
Gupta S, Navaraj WT, Lorenzelli L, Dahiya R. Ultra-thin
chips for high-performance flexible electronics. npj Flex
Electron 2018; 2: 8.
[2]
Yu KJ, Yan Z, Han M, Rogers JA. Inorganic semiconducting
materials for flexible and stretchable electronics. npj
Flex Electron 2017; 1: 4.
[3]
Noyan DI, Gadea G, Salleras M, et al. SiGe nanowire arrays based thermoelectric microgenerator. Nano Energy 2019; 57: 492-9.
[http://dx.doi.org/10.1016/j.nanoen.2018.12.050]
[http://dx.doi.org/10.1016/j.nanoen.2018.12.050]
[4]
Harame DL, Koester SJ, Freeman G, et al. The revolution in SiGe: Impact on device electronics. Appl Surf Sci 2004; 224(1–4): 9-17.
[http://dx.doi.org/10.1016/j.apsusc.2003.08.086]
[http://dx.doi.org/10.1016/j.apsusc.2003.08.086]
[5]
Huang S, He J, Li S, Cao Z, Li JA. 20-Gb/s wideband AGC amplifier with 26-dB dynamic range in 0.18-μm SiGe BiCMOS. Integration (Amst) 2021; 81: 160-6.
[http://dx.doi.org/10.1016/j.vlsi.2021.06.003]
[http://dx.doi.org/10.1016/j.vlsi.2021.06.003]
[6]
Xue Z, He J, Fang Y, et al. 10-Gb/s inductorless optical receiver in 0.18-μm SiGe BiCMOS. Microelectronics 2019; 86: 34-9.
[http://dx.doi.org/10.1016/j.mejo.2019.02.010]
[http://dx.doi.org/10.1016/j.mejo.2019.02.010]
[7]
Boztug C, Sánchez-Pérez JR, Cavallo F, Lagally MG, Paiella R. Strained-germanium nanostructures for infrared photonics. ACS Nano 2014; 8(4): 3136-51.
[http://dx.doi.org/10.1021/nn404739b] [PMID: 24597822]
[http://dx.doi.org/10.1021/nn404739b] [PMID: 24597822]
[8]
Scott SA, Lagally MG. Elastically strain-sharing nanomembranes: Flexible and transferable strained silicon and silicon–germanium alloys. J Phys D Appl Phys 2007; 40(4): R75-92.
[http://dx.doi.org/10.1088/0022-3727/40/4/R01]
[http://dx.doi.org/10.1088/0022-3727/40/4/R01]
[10]
Chen J, Ge K, Chen B, et al. Establishment of a novel functional group passivation system for the surface engineering of c-Si solar cells. Sol Energy Mater Sol Cells 2019; 195: 99-105.
[http://dx.doi.org/10.1016/j.solmat.2019.02.039]
[http://dx.doi.org/10.1016/j.solmat.2019.02.039]
[11]
Savin H, Repo P, von Gastrow G, et al. Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency. Nat Nanotechnol 2015; 10(7): 624-8.
[http://dx.doi.org/10.1038/nnano.2015.89] [PMID: 25984832]
[http://dx.doi.org/10.1038/nnano.2015.89] [PMID: 25984832]
[12]
Preissler N, Töfflinger JA, Gabriel O, et al. Passivation at the interface between liquid-phase crystallized silicon and silicon oxynitride in thin film solar cells: Passivation of liquid-phase crystallized silicon. Prog Photovolt Res Appl 2017; 25(7): 515-24.
[http://dx.doi.org/10.1002/pip.2852]
[http://dx.doi.org/10.1002/pip.2852]
[13]
Schmidt J, Peibst R, Brendel R. Surface passivation of crystalline silicon solar cells: Present and future. Sol Energy Mater Sol Cells 2018; 187: 39-54.
[http://dx.doi.org/10.1016/j.solmat.2018.06.047]
[http://dx.doi.org/10.1016/j.solmat.2018.06.047]
[14]
Niikura K, Yamahata N, Hoshi Y, et al. Enhanced photoluminescence from strained Ge-on-Insulator surface-passivated with hydrogenated amorphous Si. Mater Sci Semicond Process 2020; 115: 105104.
[http://dx.doi.org/10.1016/j.mssp.2020.105104]
[http://dx.doi.org/10.1016/j.mssp.2020.105104]
[15]
Kerr MJ, Cuevas A. Very low bulk and surface recombination in oxidized silicon wafers. Semicond Sci Technol 2002; 17(1): 35-8.
[http://dx.doi.org/10.1088/0268-1242/17/1/306]
[http://dx.doi.org/10.1088/0268-1242/17/1/306]
[16]
Yablonovitch E, Allara DL, Chang CC, Gmitter T, Bright TB. Unusually low surface-recombination velocity on silicon and germanium surfaces. Phys Rev Lett 1986; 57(2): 249-52.
[http://dx.doi.org/10.1103/PhysRevLett.57.249] [PMID: 10033759]
[http://dx.doi.org/10.1103/PhysRevLett.57.249] [PMID: 10033759]
[17]
Chhabra B, Bowden S, Opila RL, Honsberg CB. High effective minority carrier lifetime on silicon substrates using quinhydrone-methanol passivation. Appl Phys Lett 2010; 96(6): 063502.
[http://dx.doi.org/10.1063/1.3309595]
[http://dx.doi.org/10.1063/1.3309595]
[18]
Yu Y, Hu S, Huang J. Germanium-modified silicon as anodes in Si–Ge air batteries with enhanced properties. J Phys Chem Solids 2021; 157: 110226.
[http://dx.doi.org/10.1016/j.jpcs.2021.110226]
[http://dx.doi.org/10.1016/j.jpcs.2021.110226]
[19]
Liao B, Stangl R, Mueller T, Lin F, Bhatia CS, Hoex B. The effect of light soaking on crystalline silicon surface passivation by atomic layer deposited Al2O3. J Appl Phys 2013; 113(2): 024509.
[http://dx.doi.org/10.1063/1.4775595]
[http://dx.doi.org/10.1063/1.4775595]
[20]
Liu Y, Zhang J, Wu H, et al. Low-temperature synthesis TiOx passivation layer for organic-silicon heterojunction solar cell with a high open-circuit voltage. Nano Energy 2017; 34: 257-63.
[http://dx.doi.org/10.1016/j.nanoen.2017.02.024]
[http://dx.doi.org/10.1016/j.nanoen.2017.02.024]
[21]
Ardali S, Atmaca G, Lisesivdin SB, et al. The variation of temperature-dependent carrier concentration and mobility in Al-GaN/AlN/GaN heterostructure with SiN passivation: Variation of carrier concentration and mobility in AlGaN/AlN/GaN. Phys Status Solidi, B Basic Res 2015; 252(9): 1960-5.
[http://dx.doi.org/10.1002/pssb.201552135]
[http://dx.doi.org/10.1002/pssb.201552135]
[22]
De Wolf S, Kondo M. Abruptness of a-Si:H/c-Si interface revealed by carrier lifetime measurements. Appl Phys Lett 2007; 90(4): 042111.
[http://dx.doi.org/10.1063/1.2432297]
[http://dx.doi.org/10.1063/1.2432297]
[23]
Escorihuela J, Zuilhof H. Rapid surface functionalization of hydrogen-terminated silicon by alkyl silanols. J Am Chem Soc 2017; 139(16): 5870-6.
[http://dx.doi.org/10.1021/jacs.7b01106] [PMID: 28409624]
[http://dx.doi.org/10.1021/jacs.7b01106] [PMID: 28409624]
[24]
Nadtochiy A, Korotchenkov O, Schlosser V. Sonochemical modification of SiGe layers for photovoltaic applications. Phys Status Solidi, A Appl Mater Sci 2019; 216(17): 1900154.
[http://dx.doi.org/10.1002/pssa.201900154]
[http://dx.doi.org/10.1002/pssa.201900154]
[25]
Shmid V, Podolian A, Nadtochiy A, Korotchenkov O. Passivating Si and Ge surfaces using a facile sonochemical method Special Issue “Thin-film materials, devices and carrier dynamics for flexible electronics” Special Issue Editor (Zhigang Yin) Available from: https://materials.international/?page_id=1308
[26]
Shmid V, Podolian A, Nadtochiy A, Yazykov D, Semen’ko M, Korotchenkov O. Photovoltaic characterization of Si and SiGe surfaces sonochemically treated in dichloromethane. J. Nano- Electron. Phys 2020; 12(1): 01023.
[27]
Nadtochiy AB, Shmid VI, Korotchenkov OA. Miniature ultrasonic transducer for lab-on-a-chip applications. IEEE 40th International Conference on Electronics and Nanotechnology (ELNANO). 2020, pp. 425-9
[http://dx.doi.org/10.1109/ELNANO50318.2020.9088851]
[http://dx.doi.org/10.1109/ELNANO50318.2020.9088851]
[28]
Hu L, Pasta M, Mantia FL, et al. Stretchable, porous, and conductive energy textiles. Nano Lett 2010; 10(2): 708-14.
[http://dx.doi.org/10.1021/nl903949m] [PMID: 20050691]
[http://dx.doi.org/10.1021/nl903949m] [PMID: 20050691]
[29]
Nadtochiy A, Podolian A, Korotchenkov O, Schmid J, Kancsar E, Schlosser V. Water-based sonochemical cleaning in the manufacturing of high-efficiency photovoltaic silicon wafers: Water-based sonochemical cleaning in the manufacturing of high-efficiency photovoltaic silicon wafers. Phys Status Solidi, C Curr Top Solid State Phys 2011; 8(9): 2927-30.
[http://dx.doi.org/10.1002/pssc.201084062]
[http://dx.doi.org/10.1002/pssc.201084062]
[30]
Podolian A, Kozachenko V, Nadtochiy A, Borovoy N, Korotchenkov O. Photovoltage transients at fullerene-metal interfaces. J Appl Phys 2010; 107(9): 093706.
[http://dx.doi.org/10.1063/1.3407562]
[http://dx.doi.org/10.1063/1.3407562]
[31]
Kern W, Reinhardt KA. Handbook of silicon wafer cleaning technology. (2nd ed.), Norwich, CT: William Andrew Publishing 2008.
[32]
Higashi GS, Chabal YJ, Trucks GW, Raghavachari K. Ideal hydrogen termination of the Si (111) surface. Appl Phys Lett 1990; 56(7): 656-8.
[http://dx.doi.org/10.1063/1.102728]
[http://dx.doi.org/10.1063/1.102728]
[33]
Capper P, Ed. Springer handbook of electronic and photonic materials. (2nd ed.), Cham, Switzerland: Springer International Publishing 2017.
[34]
Rabie MA, Haddara YM, Carette J. A kinetic model for the oxidation of silicon germanium alloys. J Appl Phys 2005; 98(7): 074904.
[http://dx.doi.org/10.1063/1.2060927]
[http://dx.doi.org/10.1063/1.2060927]
[35]
Nicolet M-A, Liu W-S. Oxidation of GeSi. Microelectron Eng 1995; 28(1-4): 185-91.
[http://dx.doi.org/10.1016/0167-9317(95)00040-F]
[http://dx.doi.org/10.1016/0167-9317(95)00040-F]
[36]
Sun S, Sun Y, Liu Z, Lee D-I, Peterson S, Pianetta P. Surface termination and roughness of Ge(100) cleaned by HF and HCl solutions. Appl Phys Lett 2006; 88(2): 021903.
[http://dx.doi.org/10.1063/1.2162699]
[http://dx.doi.org/10.1063/1.2162699]
[37]
Gaubas E, Simoen E, Vanhellemont J. Review-carrier lifetime spectroscopy for defect characterization in semiconductor materials and devices. ECS J Solid State Sci Technol 2016; 5(4): 3108-37.
[http://dx.doi.org/10.1149/2.0201604jss]
[http://dx.doi.org/10.1149/2.0201604jss]
[38]
Roberts MM, Klein LJ, Savage DE, et al. Elastically relaxed free-standing strained-silicon nanomembranes. Nat Mater 2006; 5(5): 388-93.
[http://dx.doi.org/10.1038/nmat1606] [PMID: 16604081]
[http://dx.doi.org/10.1038/nmat1606] [PMID: 16604081]
[39]
Iyer SS, Patton GL, Harame DL, Stork JMC, Crabbé EF, Meyerson BS. Narrow band gap base heterojunction bipolar transistors us-ing Si-Ge alloys. Thin Solid Films 1990; 184(1-2): 153-62.
[http://dx.doi.org/10.1016/0040-6090(90)90409-7]
[http://dx.doi.org/10.1016/0040-6090(90)90409-7]
[40]
Zaumseil P, Yamamoto Y, Bauer A, Schubert MA, Schroeder T. X-ray characterization of Ge epitaxially grown on nanostructured Si(001) wafers. J Appl Phys 2011; 109(2): 023511.
[http://dx.doi.org/10.1063/1.3537829]
[http://dx.doi.org/10.1063/1.3537829]
[41]
Williamson DL. Microstructure of amorphous and microcrystalline Si and SiGe alloys using X-rays and neutrons. Sol Energy Mater Sol Cells 2003; 78(1–4): 41-84.
[http://dx.doi.org/10.1016/S0927-0248(02)00433-6]
[http://dx.doi.org/10.1016/S0927-0248(02)00433-6]
[42]
Sun X-H, Li C-P, Wong N-B, Lee C-S, Lee S-T, Teo B-K. Templating effect of hydrogen-passivated silicon nanowires in the production of hydrocarbon nanotubes and nanoonions via sonochemical reactions with common organic solvents under ambient conditions. J Am Chem Soc 2002; 124(50): 14856-7.
[http://dx.doi.org/10.1021/ja0283706] [PMID: 12475321]
[http://dx.doi.org/10.1021/ja0283706] [PMID: 12475321]
[43]
Abderrafi K, García Calzada R, Gongalsky MB, et al. Silicon nanocrystals produced by nanosecond laser ablation in an organic liquid. J Phys Chem C 2011; 115(12): 5147-51.
[http://dx.doi.org/10.1021/jp109400v]
[http://dx.doi.org/10.1021/jp109400v]
[44]
Suslick KS. Sonochemistry. Science 1990; 247(4949): 1439-45.
[http://dx.doi.org/10.1126/science.247.4949.1439] [PMID: 17791211]
[http://dx.doi.org/10.1126/science.247.4949.1439] [PMID: 17791211]
[45]
Royea WJ, Juang A, Lewis NS. Preparation of air-stable, low recombination velocity Si(111) surfaces through alkyl termination. Appl Phys Lett 2000; 77(13): 1988-90.
[http://dx.doi.org/10.1063/1.1312203]
[http://dx.doi.org/10.1063/1.1312203]
[46]
Hunger R, Fritsche R, Jaeckel B, Jaegermann W, Webb LJ, Lewis NS. Chemical and electronic characterization of methyl-terminated Si(111) surfaces by high-resolution synchrotron photoelectron spectroscopy. Phys Rev B Condens Matter Mater Phys 2005; 72(4): 045317.
[http://dx.doi.org/10.1103/PhysRevB.72.045317]
[http://dx.doi.org/10.1103/PhysRevB.72.045317]
[47]
Wong KT, Kim Y-G, Soriaga MP, Brunschwig BS, Lewis NS. Synthesis and characterization of atomically flat methyl-terminated Ge(111) surfaces. J Am Chem Soc 2015; 137(28): 9006-14.
[http://dx.doi.org/10.1021/jacs.5b03339] [PMID: 26154680]
[http://dx.doi.org/10.1021/jacs.5b03339] [PMID: 26154680]
[48]
Knapp D, Brunschwig BS, Lewis NS. Chemical, electronic, and electrical properties of alkylated Ge(111) surfaces. J Phys Chem C 2010; 114(28): 12300-7.
[http://dx.doi.org/10.1021/jp101375x]
[http://dx.doi.org/10.1021/jp101375x]
[49]
Knapp D, Brunschwig BS, Lewis NS. Transmission infrared spectra of CH3–, CD3–, and C10H21–Ge(111) surfaces. J Phys Chem C 2011; 115(33): 16389-97.
[http://dx.doi.org/10.1021/jp110550t]
[http://dx.doi.org/10.1021/jp110550t]
Article Metrics
3