Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328148
U. Mishra, J. Shealy
InP based HEMT technology has evolved from research in a few labs into the mainstream of high speed microwave and millimeter wave circuits. InP HEMTs produce lower noise figures, higher gain, and higher cut-off frequencies in comparison to the best GaAs based FETs. Recent improvement in the performance of the GaInAs-channel HEMT may be attributed to: (i) obtaining superior transport properties in higher In mole-fraction channels; (ii) reducing parasitic resistance by self-aligning the ohmic contacts to the gate; and (iii) reducing the gate-length while maintaining a high aspect ratio. These efforts combined have led to a successful fabrication of ultrafast 0.1 /spl mu/m gate-length HEMTs in the late 80's to present state-of-the-art 0.05 /spl mu/m gate-lengths in the early 90's. Consequently, they are now the most promising candidate for low noise amplifiers, millimeter wave power amplification, broadband distributed amplifiers, and high frequency oscillator circuits. A review of the low noise performance is presented along with recent diversification in the InP based HEMT technology to microwave and millimeter wave power amplification.<>
{"title":"InP-based HEMTs: status and potential","authors":"U. Mishra, J. Shealy","doi":"10.1109/ICIPRM.1994.328148","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328148","url":null,"abstract":"InP based HEMT technology has evolved from research in a few labs into the mainstream of high speed microwave and millimeter wave circuits. InP HEMTs produce lower noise figures, higher gain, and higher cut-off frequencies in comparison to the best GaAs based FETs. Recent improvement in the performance of the GaInAs-channel HEMT may be attributed to: (i) obtaining superior transport properties in higher In mole-fraction channels; (ii) reducing parasitic resistance by self-aligning the ohmic contacts to the gate; and (iii) reducing the gate-length while maintaining a high aspect ratio. These efforts combined have led to a successful fabrication of ultrafast 0.1 /spl mu/m gate-length HEMTs in the late 80's to present state-of-the-art 0.05 /spl mu/m gate-lengths in the early 90's. Consequently, they are now the most promising candidate for low noise amplifiers, millimeter wave power amplification, broadband distributed amplifiers, and high frequency oscillator circuits. A review of the low noise performance is presented along with recent diversification in the InP based HEMT technology to microwave and millimeter wave power amplification.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129692329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328176
A. Bensaada, R. Cochrane, R. Masut
We characterize sulfur diffusion from heavily doped (n/spl sim/10/sup 19/ cm/sup -3/) InP:S (001) substrates into nominally undoped Ga/sub x/In/sub 1-x/P (0/spl les/x/spl les/0.2) epilayers during growth by low-pressure MOCVD. The composition, relaxation and dislocation density of the samples have been studied by high resolution X-ray diffraction and in-depth doping profiles have been obtained using a C-V electrochemical profiler. The analysis of these profiles shows that as the Ga content of these thick (/spl sim/1 /spl mu/m) samples is increased, a rapid enhancement of the sulfur diffusion from the substrate is observed. This enhancement is a consequence of the generation of an increasing number of dislocations initially caused by the mismatch. The structural defects act as pipes inside which the diffusion coefficient (D/sub d/) of sulfur atoms is calculated to be 6 orders of magnitude higher than that of the undislocated material (D/sub l/). Value of D/sub lspl sim/2/spl times/10/sup -17/ cm/sup 2s at the growth temperature of 640/spl deg/C have been deduced.<>
{"title":"Dislocation-enhanced diffusion in heteroepitaxial GaInP/InP:S","authors":"A. Bensaada, R. Cochrane, R. Masut","doi":"10.1109/ICIPRM.1994.328176","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328176","url":null,"abstract":"We characterize sulfur diffusion from heavily doped (n/spl sim/10/sup 19/ cm/sup -3/) InP:S (001) substrates into nominally undoped Ga/sub x/In/sub 1-x/P (0/spl les/x/spl les/0.2) epilayers during growth by low-pressure MOCVD. The composition, relaxation and dislocation density of the samples have been studied by high resolution X-ray diffraction and in-depth doping profiles have been obtained using a C-V electrochemical profiler. The analysis of these profiles shows that as the Ga content of these thick (/spl sim/1 /spl mu/m) samples is increased, a rapid enhancement of the sulfur diffusion from the substrate is observed. This enhancement is a consequence of the generation of an increasing number of dislocations initially caused by the mismatch. The structural defects act as pipes inside which the diffusion coefficient (D/sub d/) of sulfur atoms is calculated to be 6 orders of magnitude higher than that of the undislocated material (D/sub l/). Value of D/sub lspl sim/2/spl times/10/sup -17/ cm/sup 2s at the growth temperature of 640/spl deg/C have been deduced.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128516535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328182
C. Klingelhofer, S. Krawczyk, F. Nuban, M. Gendry
A wide range of InAlAs/InGaAs/InAlAs/InP and InGaAs/InP lattice mismatched heterostructures with different thicknesses and compositions of the InGaAs layer were grown on InP (001) by Molecular Beam Epitaxy (MBE) and investigated with high spatial resolution spectrally resolved scanning photoluminescence. The objective of this contribution is to demonstrate that different types of extended defects (misfit dislocations, threading dislocations, oval-shaped defects) and structural micro-heterogeneity in the InGaAs layers induce significant short range changes of the spectral parameters of the photoluminescence bands.<>
{"title":"Demonstration of short range non-uniformities of the spectral parameters of photoluminescence bands in lattice mismatched InAlAs/InGaAs/InAlAs/InP heterostructures","authors":"C. Klingelhofer, S. Krawczyk, F. Nuban, M. Gendry","doi":"10.1109/ICIPRM.1994.328182","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328182","url":null,"abstract":"A wide range of InAlAs/InGaAs/InAlAs/InP and InGaAs/InP lattice mismatched heterostructures with different thicknesses and compositions of the InGaAs layer were grown on InP (001) by Molecular Beam Epitaxy (MBE) and investigated with high spatial resolution spectrally resolved scanning photoluminescence. The objective of this contribution is to demonstrate that different types of extended defects (misfit dislocations, threading dislocations, oval-shaped defects) and structural micro-heterogeneity in the InGaAs layers induce significant short range changes of the spectral parameters of the photoluminescence bands.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"254 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122365318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328242
S. Ojha, R. Turner, J. Stagg, D. Boyle, G. Thompson
Fabrication of integrated optoelectronic devices, such as for WDM applications, requires reliable and controlled processing and the integration of various components such as mirrors, gratings, waveguides, lasers and detectors. We have recently reported fabrication and device characteristics of a low loss multichannel demultiplexer. One of the key elements of this device was fabrication of low loss parabolic mirrors. An RIE process based on methane, hydrogen and carbon dioxide gases was developed for etching vertical mirrors through a double heterostructure. In this paper work we report development of processes, such as controlled dry etching of detector and shallow waveguides by using laser interferometer for process control, and masked overgrowth for active passive integration.<>
{"title":"Monitoring and control of fabrication processes for integrated optics devices","authors":"S. Ojha, R. Turner, J. Stagg, D. Boyle, G. Thompson","doi":"10.1109/ICIPRM.1994.328242","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328242","url":null,"abstract":"Fabrication of integrated optoelectronic devices, such as for WDM applications, requires reliable and controlled processing and the integration of various components such as mirrors, gratings, waveguides, lasers and detectors. We have recently reported fabrication and device characteristics of a low loss multichannel demultiplexer. One of the key elements of this device was fabrication of low loss parabolic mirrors. An RIE process based on methane, hydrogen and carbon dioxide gases was developed for etching vertical mirrors through a double heterostructure. In this paper work we report development of processes, such as controlled dry etching of detector and shallow waveguides by using laser interferometer for process control, and masked overgrowth for active passive integration.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126668391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328225
D. Wilt
The reliability of InGaAs/InP semiconductor lasers at typical use conditions is extremely high. This has led to their successful deployment in applications ranging from terrestrial long-haul communication links (MTTF/spl ges/25 years) to transoceanic submarine cable systems (MTTF/spl ges/300 years). At the same time, extremely long service lifetimes and high system reliability requirements make the quantification of device reliability an inexact science, since the period for study must of necessity be a small fraction of the desired system life.<>
{"title":"Reliability of InGaAs/InP semiconductor diode lasers","authors":"D. Wilt","doi":"10.1109/ICIPRM.1994.328225","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328225","url":null,"abstract":"The reliability of InGaAs/InP semiconductor lasers at typical use conditions is extremely high. This has led to their successful deployment in applications ranging from terrestrial long-haul communication links (MTTF/spl ges/25 years) to transoceanic submarine cable systems (MTTF/spl ges/300 years). At the same time, extremely long service lifetimes and high system reliability requirements make the quantification of device reliability an inexact science, since the period for study must of necessity be a small fraction of the desired system life.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120951680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328260
P. Rojo-Romeo, P. Viktorovitch, J. Leclercq, X. Letartre, J. Tardy, M. Oustric, M. Gendry
In this work, we present a study of various low-frequency noise (LFN) sources in InAlAs/InGaAs MODFET structures. The contributions of the main noise sources-drain and source contact resistance fluctuations, channel charge fluctuations and gate current noise-are separated by measuring the drain current power noise spectrum on uncompleted, gate free MODFET structures of different channel lengths. A variety of MBE grown structures was investigated: /spl delta/- and uniformly-doped MODFET's: devices with lattice-matched and strained channel. Also experiments were performed on devices with different source and drain ohmic contacts.<>
{"title":"Low frequency noise sources in InAlAs/InGaAs MODFET's","authors":"P. Rojo-Romeo, P. Viktorovitch, J. Leclercq, X. Letartre, J. Tardy, M. Oustric, M. Gendry","doi":"10.1109/ICIPRM.1994.328260","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328260","url":null,"abstract":"In this work, we present a study of various low-frequency noise (LFN) sources in InAlAs/InGaAs MODFET structures. The contributions of the main noise sources-drain and source contact resistance fluctuations, channel charge fluctuations and gate current noise-are separated by measuring the drain current power noise spectrum on uncompleted, gate free MODFET structures of different channel lengths. A variety of MBE grown structures was investigated: /spl delta/- and uniformly-doped MODFET's: devices with lattice-matched and strained channel. Also experiments were performed on devices with different source and drain ohmic contacts.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128764632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328303
T. Chiu, W. Tsang, R. Kapre, M.D. Williams, J. F. Ferguson
An etching process with real-time monitoring of each monolayer removed is demonstrated. The etching is accomplished by injecting AsCl/sub 3/ or PCl/sub 3/ gas directly into the growth chamber at a temperature comparable to the typical growth temperature in the same system. This method allows instant switching between the etch and the growth modes. The etching rate of GaAs is insensitive to the substrate temperature, which is important for a reproducible etching technology. A roughening mechanism of the etched surface due to a lack of cation diffusion is identified. Using a pulse etching mode and a migration enhanced smoothing, mirror like morphology has been obtained in the etching of InP. A layer-by-layer etching process and a in-situ monitoring technique at atomic scale are essential for a true monolayer etching technology.<>
{"title":"Monolayer control of chemical beam etching for regrowth","authors":"T. Chiu, W. Tsang, R. Kapre, M.D. Williams, J. F. Ferguson","doi":"10.1109/ICIPRM.1994.328303","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328303","url":null,"abstract":"An etching process with real-time monitoring of each monolayer removed is demonstrated. The etching is accomplished by injecting AsCl/sub 3/ or PCl/sub 3/ gas directly into the growth chamber at a temperature comparable to the typical growth temperature in the same system. This method allows instant switching between the etch and the growth modes. The etching rate of GaAs is insensitive to the substrate temperature, which is important for a reproducible etching technology. A roughening mechanism of the etched surface due to a lack of cation diffusion is identified. Using a pulse etching mode and a migration enhanced smoothing, mirror like morphology has been obtained in the etching of InP. A layer-by-layer etching process and a in-situ monitoring technique at atomic scale are essential for a true monolayer etching technology.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130726520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328171
J. L. de Miguel, E. Gomez-Salas, J.L. Martin
The expressions given by the kinematic theory of X-ray diffraction have been particularized to strained layers multiple quantum wells (SL-MQW) of GaInAs/GaInAsP. A procedure based on these expressions is proposed that, with a proper design of the test sample, yields the layer thicknesses and composition of the SL-MQW. This procedure is applied to a sample containing a 20 periods SL-MQW of GaInAs/GaInAsP emitting at 1.55 /spl mu/m, and the results double checked using the dynamical theory of X-ray diffraction. This procedure is used for the fast and accurate assessment of SL-MQW on a routine basis.<>
{"title":"Assessment of the structural parameters of GaInAs/GaInAsP strained layer multiquantum wells by X-ray diffraction","authors":"J. L. de Miguel, E. Gomez-Salas, J.L. Martin","doi":"10.1109/ICIPRM.1994.328171","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328171","url":null,"abstract":"The expressions given by the kinematic theory of X-ray diffraction have been particularized to strained layers multiple quantum wells (SL-MQW) of GaInAs/GaInAsP. A procedure based on these expressions is proposed that, with a proper design of the test sample, yields the layer thicknesses and composition of the SL-MQW. This procedure is applied to a sample containing a 20 periods SL-MQW of GaInAs/GaInAsP emitting at 1.55 /spl mu/m, and the results double checked using the dynamical theory of X-ray diffraction. This procedure is used for the fast and accurate assessment of SL-MQW on a routine basis.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131016330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328179
P. Regreny, G. Jacob, M. Gendry, G. Hollinger, M. Gauneau, D. Lecrosnier, T. Benyattou
In this work we investigate the aging behavior of InP substrates prepared with 2 different epi-ready processes based on "thin" 4-5 /spl Aring/ and "thick" 7-8 /spl Aring/ oxide layers. The oxide layers are characterized by X-ray photoelectron spectroscopy (XPS) after storage in both air and nitrogen. While there is no variation of the oxide thickness when substrates are stored under nitrogen, for a "thin" 4-5 /spl Aring/ oxide layer stored in air, the oxide thickness increases with time. However the photoluminescence behavior of MBE grown InAs/AlInAs quantum wells localised near the interface and SIMS profiles show no aging effect after 6 months if an optimized oxide desorption procedure (In stabilization of the surface) is used.<>
{"title":"Aging behavior of InP substrates prepared with 2 different epi-ready processes","authors":"P. Regreny, G. Jacob, M. Gendry, G. Hollinger, M. Gauneau, D. Lecrosnier, T. Benyattou","doi":"10.1109/ICIPRM.1994.328179","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328179","url":null,"abstract":"In this work we investigate the aging behavior of InP substrates prepared with 2 different epi-ready processes based on \"thin\" 4-5 /spl Aring/ and \"thick\" 7-8 /spl Aring/ oxide layers. The oxide layers are characterized by X-ray photoelectron spectroscopy (XPS) after storage in both air and nitrogen. While there is no variation of the oxide thickness when substrates are stored under nitrogen, for a \"thin\" 4-5 /spl Aring/ oxide layer stored in air, the oxide thickness increases with time. However the photoluminescence behavior of MBE grown InAs/AlInAs quantum wells localised near the interface and SIMS profiles show no aging effect after 6 months if an optimized oxide desorption procedure (In stabilization of the surface) is used.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131597549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1994-03-27DOI: 10.1109/ICIPRM.1994.328300
M. Gault, H. Matsuura, K. Furuya, P. Mawby, M. Towers
A new quantum effect device which is capable of highly coherent electron emission is proposed and analysed. The device is predicted to be highly successful with the coherency/current density combination easily controlled by the applied bias. In addition it may offer the potential for ultra-fast switching between coherent and incoherent states.<>
{"title":"A new quantum effect device for coherent electron emission","authors":"M. Gault, H. Matsuura, K. Furuya, P. Mawby, M. Towers","doi":"10.1109/ICIPRM.1994.328300","DOIUrl":"https://doi.org/10.1109/ICIPRM.1994.328300","url":null,"abstract":"A new quantum effect device which is capable of highly coherent electron emission is proposed and analysed. The device is predicted to be highly successful with the coherency/current density combination easily controlled by the applied bias. In addition it may offer the potential for ultra-fast switching between coherent and incoherent states.<<ETX>>","PeriodicalId":161711,"journal":{"name":"Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131872922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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