Pub Date : 2002-12-11DOI: 10.1109/COMMAD.2002.1237259
A. Djurišić, A. Rakić, M. L. Majewski
In this work, we present genetic algorithm based approach for the design of asymmetric Bragg mirrors for the microcavity organic light emitting diodes (OLEDs) applications. The phase shift of the Bragg mirror is calculated using the matrix formulation for light propagation through a thin film multilayer. The objective function to be minimized is the wavelength shift in Ag/Alq/sub 3//TPD/ITO/Bragg mirror/glass device, where ITO is indium tin oxide, AIq/sub 3/ is tris (8-hydroxyquinoline) aluminum, and TPD is N,N'-disphenyl-N,N'-bis(3-methylphenyl)-1,1'-disphenyl-4,4'-diamine, which are commonly used emitting and hole transport materials. We have considered TiO/sub 2//SiO/sub 2/ and Si/sub 3/N/sub 4//SiO/sub 2/ Bragg mirrors, where thickness of each layer in the mirror is determined by minimizing the emission wavelength shift using a genetic algorithm. Simulation results show that the use of asymmetric Bragg mirrors may enable reduction of the emission wavelength shift in organic microcavity devices.
{"title":"Asymmetric Bragg mirror design for organic microcavity light emitting diodes","authors":"A. Djurišić, A. Rakić, M. L. Majewski","doi":"10.1109/COMMAD.2002.1237259","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237259","url":null,"abstract":"In this work, we present genetic algorithm based approach for the design of asymmetric Bragg mirrors for the microcavity organic light emitting diodes (OLEDs) applications. The phase shift of the Bragg mirror is calculated using the matrix formulation for light propagation through a thin film multilayer. The objective function to be minimized is the wavelength shift in Ag/Alq/sub 3//TPD/ITO/Bragg mirror/glass device, where ITO is indium tin oxide, AIq/sub 3/ is tris (8-hydroxyquinoline) aluminum, and TPD is N,N'-disphenyl-N,N'-bis(3-methylphenyl)-1,1'-disphenyl-4,4'-diamine, which are commonly used emitting and hole transport materials. We have considered TiO/sub 2//SiO/sub 2/ and Si/sub 3/N/sub 4//SiO/sub 2/ Bragg mirrors, where thickness of each layer in the mirror is determined by minimizing the emission wavelength shift using a genetic algorithm. Simulation results show that the use of asymmetric Bragg mirrors may enable reduction of the emission wavelength shift in organic microcavity devices.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131331619","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237236
D. Shim, Hae-Seok Park, K. Na, Wonseo Choi, Jun-sik Hwang, Sang-on Choi
This paper describes a MEMS-based micro-fluxgate magnetic sensor composed of solenoid driving coil, sensing coil and rectangular-ring shaped magnetic core. Solenoid coils and magnetic core were separated by benzocyclobutene (BCB) having high resistivity and good planarization characteristics. To take advantage of low cost, small size and low power consumption, MEMS technology was used to fabricate micro fluxgate sensor. Copper coil with 20 /spl mu/m width and 3.5/spl mu/m thickness was electroplated on Cr (300/spl Aring/)/Au (1500/spl Aring/) films for driving and sensing coils. We designed the magnetic core into a rectangular-ring shape to reduce the magnetic flux leakage. Permalloy (NiO/sub 0.8/Fe/sub 0.2/) film with the thickness of 2 /spl mu/m was electroplated under 2000 gauss to induce magnetic anisotropy. The magnetic core had the high DC effective permeability of /spl sim/1,100 and coercivity of /spl sim/0.1 Oe. The fabricated fluxgate sensor had the sensitivity of /spl sim/650 V/T and power consumption of 40 mW at the driving frequency of 2 MHz and the driving voltage of 5 Vp-p.
{"title":"Micro fluxgate sensor using solenoid driving and sensing coils","authors":"D. Shim, Hae-Seok Park, K. Na, Wonseo Choi, Jun-sik Hwang, Sang-on Choi","doi":"10.1109/COMMAD.2002.1237236","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237236","url":null,"abstract":"This paper describes a MEMS-based micro-fluxgate magnetic sensor composed of solenoid driving coil, sensing coil and rectangular-ring shaped magnetic core. Solenoid coils and magnetic core were separated by benzocyclobutene (BCB) having high resistivity and good planarization characteristics. To take advantage of low cost, small size and low power consumption, MEMS technology was used to fabricate micro fluxgate sensor. Copper coil with 20 /spl mu/m width and 3.5/spl mu/m thickness was electroplated on Cr (300/spl Aring/)/Au (1500/spl Aring/) films for driving and sensing coils. We designed the magnetic core into a rectangular-ring shape to reduce the magnetic flux leakage. Permalloy (NiO/sub 0.8/Fe/sub 0.2/) film with the thickness of 2 /spl mu/m was electroplated under 2000 gauss to induce magnetic anisotropy. The magnetic core had the high DC effective permeability of /spl sim/1,100 and coercivity of /spl sim/0.1 Oe. The fabricated fluxgate sensor had the sensitivity of /spl sim/650 V/T and power consumption of 40 mW at the driving frequency of 2 MHz and the driving voltage of 5 Vp-p.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114151276","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237214
A. H. Ramelan, K. Butcher, E. Goldys
The extent of oxidation and growth derived oxygen contamination for Al/sub 0.05/Ga/sub 0.95/Sb grown by metalorganic chemical vapour deposition (MOCVD) were systematically investigated by X-ray photoelectron spectroscopy (XPS) using a system with high-energy resolution. The Sb3d/sub 5/2/ and O1s peaks are well resolved and the Ga3d peaks are also well resolved. As expected, all samples investigated show oxide layers (Al/sub 2/O/sub 3/, Sb/sub 2/O/sub 2/ and Ga/sub 2/O/sub 5/) on their surfaces. In particular the percentage of aluminium-oxide was very high compared with a small percentage of AlSb. This indicates that the surface aluminium is very reactive to oxygen from the environment. Carbon content on the surface was also very high. Deeper into the layer, the carbon signal was below the detection limit of XPS and secondary ion mass spectroscopy (SIMS) indicating that the carbon was due to atmospheric exposure. The results indicate extremely low carbon content for Al/sub 0.05/Ga/sub 0.95/Sb epilayers grown using TMAl, TMGa and TMSb as metalorganic precursors in an MOCVD system.
{"title":"X-ray photoelectron spectroscopy of Al/sub x/Ga/sub 1-x/Sb grown by metalorganic chemical vapour deposition","authors":"A. H. Ramelan, K. Butcher, E. Goldys","doi":"10.1109/COMMAD.2002.1237214","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237214","url":null,"abstract":"The extent of oxidation and growth derived oxygen contamination for Al/sub 0.05/Ga/sub 0.95/Sb grown by metalorganic chemical vapour deposition (MOCVD) were systematically investigated by X-ray photoelectron spectroscopy (XPS) using a system with high-energy resolution. The Sb3d/sub 5/2/ and O1s peaks are well resolved and the Ga3d peaks are also well resolved. As expected, all samples investigated show oxide layers (Al/sub 2/O/sub 3/, Sb/sub 2/O/sub 2/ and Ga/sub 2/O/sub 5/) on their surfaces. In particular the percentage of aluminium-oxide was very high compared with a small percentage of AlSb. This indicates that the surface aluminium is very reactive to oxygen from the environment. Carbon content on the surface was also very high. Deeper into the layer, the carbon signal was below the detection limit of XPS and secondary ion mass spectroscopy (SIMS) indicating that the carbon was due to atmospheric exposure. The results indicate extremely low carbon content for Al/sub 0.05/Ga/sub 0.95/Sb epilayers grown using TMAl, TMGa and TMSb as metalorganic precursors in an MOCVD system.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127233236","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237233
A. Trinchi, K. Galatsis, Y.X. Li, W. Wlodarski, S. Russo, J. du Plesis, B. Rout
Gallium-Zinc mixed metal oxides have been fabricated by the sol-gel process and tested towards oxygen gas. These films were deposited on alumina transducers with interdigital electrodes for gas sensing measurements and on single crystal silicon substrates for microcharacterization. X-ray Photoelectron Spectroscopy (XPS) and Rutherford Backscattering Spectrometry (RBS) showed that the actual concentrations in Ga-Zn oxide thin films differ from the nominal values in the prepared solutions as a function of annealing temperature. Furthermore, the concentration of Zn decreases with a rise of sample annealing temperature. It was found that by increasing the amount of Zn in the sensor film, the operating temperature decreased as well as the base resistance.
{"title":"Properties of Ga-Zn based mixed oxides for gas sensing applications","authors":"A. Trinchi, K. Galatsis, Y.X. Li, W. Wlodarski, S. Russo, J. du Plesis, B. Rout","doi":"10.1109/COMMAD.2002.1237233","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237233","url":null,"abstract":"Gallium-Zinc mixed metal oxides have been fabricated by the sol-gel process and tested towards oxygen gas. These films were deposited on alumina transducers with interdigital electrodes for gas sensing measurements and on single crystal silicon substrates for microcharacterization. X-ray Photoelectron Spectroscopy (XPS) and Rutherford Backscattering Spectrometry (RBS) showed that the actual concentrations in Ga-Zn oxide thin films differ from the nominal values in the prepared solutions as a function of annealing temperature. Furthermore, the concentration of Zn decreases with a rise of sample annealing temperature. It was found that by increasing the amount of Zn in the sensor film, the operating temperature decreased as well as the base resistance.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126771177","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237261
D. Debuf, R. Corkish
Semiconductor material characterization in terms of defect parameters is presently evaluated experimentally by applying the Shockley-Read-Hall (SRH) recombination time constant expression. A recent analytic solution to the SRH rate equations extended to differential rate equations for two multiple defect level systems, yields a solution derived without an approximation. In terms of material characterisation, this exact solution is shown to provide detailed information on multiple level depths in contrast to the existing theory, which relies on one dominant single level. Furthermore, for semiconductor samples known to be predominantly doped with one defect species, it is shown theoretically that the dominant decay is influenced by the other defect species present in the semiconductor sample.
{"title":"Recombination via discrete defect levels with application to semiconductor material characterisation","authors":"D. Debuf, R. Corkish","doi":"10.1109/COMMAD.2002.1237261","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237261","url":null,"abstract":"Semiconductor material characterization in terms of defect parameters is presently evaluated experimentally by applying the Shockley-Read-Hall (SRH) recombination time constant expression. A recent analytic solution to the SRH rate equations extended to differential rate equations for two multiple defect level systems, yields a solution derived without an approximation. In terms of material characterisation, this exact solution is shown to provide detailed information on multiple level depths in contrast to the existing theory, which relies on one dominant single level. Furthermore, for semiconductor samples known to be predominantly doped with one defect species, it is shown theoretically that the dominant decay is influenced by the other defect species present in the semiconductor sample.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"385 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116009567","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237251
L. C. Castro, D. L. John, D. Pulfrey
Issues pertinent to the development of a compact model for predicting the drain current-voltage characteristics of coaxial-geometry, Schottky-barrier, carbon-nanotube field-effect transistors are discussed. Information on the non-equilibrium barrier shapes at the source-tube and drain-tube contacts is inferred from exact 2-D solutions to Poisson's equation at equilibrium and Laplace's equation. This information is then used in a non-equilibrium flux approach to create a model that accounts for tunneling through both barriers and computes the drain current in the case of ballistic transport. For (16,0) tubes and a gate/tube-radius ratio of 10, saturation drain currents of about 1 /spl mu/m are predicted.
{"title":"Towards a compact model for Schottky-barrier nanotube FETs","authors":"L. C. Castro, D. L. John, D. Pulfrey","doi":"10.1109/COMMAD.2002.1237251","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237251","url":null,"abstract":"Issues pertinent to the development of a compact model for predicting the drain current-voltage characteristics of coaxial-geometry, Schottky-barrier, carbon-nanotube field-effect transistors are discussed. Information on the non-equilibrium barrier shapes at the source-tube and drain-tube contacts is inferred from exact 2-D solutions to Poisson's equation at equilibrium and Laplace's equation. This information is then used in a non-equilibrium flux approach to create a model that accounts for tunneling through both barriers and computes the drain current in the case of ballistic transport. For (16,0) tubes and a gate/tube-radius ratio of 10, saturation drain currents of about 1 /spl mu/m are predicted.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116645679","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237285
S. Lee, G. Ditmer, N. Singh, C. Hodson, A. Goodyear, M. Cooke
Plasma enhanced chemical vapour deposition (PECVD) was used in the development of silica layers for use in planar lightwave circuit fabrication. These high-rate (>200 nm/min) processes are tailored specifically for the thick-film (5/spl sim/15 /spl mu/m) films required for these applications A GeH/sub 4/ addition to the process was used to deposit the core layer, controlling the core-clad refractive index (RI) difference in the range of 0.2%-1.65%. Undoped SiO/sub 2/ and Ge-doped SiO/sub 2/ films up to 10 /spl mu/m have been deposited on to 4" Si <100> wafers. The 'as deposited' and 'annealed' film properties: film uniformity, RI, RI uniformity and stress have been compared. The upper cladding layer in an optical planar waveguide is typically formed using boron and phosphorus doped films (BPSG) which provides the necessary reflow characteristics. Refractive index uniformity of /spl plusmn/0.0003 across 4" silicon wafers was achieved on all films after annealing. The core layer was shown to be capable of producing optical losses of <0.1 dB/cm when processed into a waveguide.
{"title":"Thick-film doped-oxide deposition processes for applications in planar lightwave circuit fabrication","authors":"S. Lee, G. Ditmer, N. Singh, C. Hodson, A. Goodyear, M. Cooke","doi":"10.1109/COMMAD.2002.1237285","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237285","url":null,"abstract":"Plasma enhanced chemical vapour deposition (PECVD) was used in the development of silica layers for use in planar lightwave circuit fabrication. These high-rate (>200 nm/min) processes are tailored specifically for the thick-film (5/spl sim/15 /spl mu/m) films required for these applications A GeH/sub 4/ addition to the process was used to deposit the core layer, controlling the core-clad refractive index (RI) difference in the range of 0.2%-1.65%. Undoped SiO/sub 2/ and Ge-doped SiO/sub 2/ films up to 10 /spl mu/m have been deposited on to 4\" Si <100> wafers. The 'as deposited' and 'annealed' film properties: film uniformity, RI, RI uniformity and stress have been compared. The upper cladding layer in an optical planar waveguide is typically formed using boron and phosphorus doped films (BPSG) which provides the necessary reflow characteristics. Refractive index uniformity of /spl plusmn/0.0003 across 4\" silicon wafers was achieved on all films after annealing. The core layer was shown to be capable of producing optical losses of <0.1 dB/cm when processed into a waveguide.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130118391","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237268
K. Prasad, X. Yuan, C. Li, R. Kumar
In this paper, we compare the experimental results on the suitability of oxygen or nitrogen containing SiC (SiCO or SiCN) with conventional SiN as a capping layer to prevent Cu diffusion into interlevel dielectric (ILD) layer in a typical Cu based interconnect structure. In addition to reducing the dielectric constant (k) value of the barrier, SiCN and SiCO show comparable performance in terms of preventing the Cu diffusion as well as offering good dielectric breakdown strength.
{"title":"Evaluation of diffusion barrier layers in Cu interconnects","authors":"K. Prasad, X. Yuan, C. Li, R. Kumar","doi":"10.1109/COMMAD.2002.1237268","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237268","url":null,"abstract":"In this paper, we compare the experimental results on the suitability of oxygen or nitrogen containing SiC (SiCO or SiCN) with conventional SiN as a capping layer to prevent Cu diffusion into interlevel dielectric (ILD) layer in a typical Cu based interconnect structure. In addition to reducing the dielectric constant (k) value of the barrier, SiCN and SiCO show comparable performance in terms of preventing the Cu diffusion as well as offering good dielectric breakdown strength.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123016859","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237180
M. Buda, H. Tan, L. Fu, L. Josyula, C. Jagadish
This paper demonstrates the improvement of kink-free operation in InGaAs/GaAs/AlGaAs high power, ridge waveguide laser diodes. Results show that when the thickness of the insulator layer is reduced below 200 nm and Ti/Pt/Au is used as the p-type metallization, significant absorption outside the ridge occurs as a result of the penetration of the vertical optical field into the absorptive metal layers. This effect can be used to introduce selective loss for the first order lateral mode. Hence, this study has shown that the kink-free operation can be improved by 30 to 50% in 980 nm emitting laser diodes when the thickness of the SiO/sub 2/ insulator is reduced to 50 to 75 nm.
{"title":"Improvement of kink-free operation in InGaAs/GaAs/AlGaAs high power, ridge waveguide laser diodes","authors":"M. Buda, H. Tan, L. Fu, L. Josyula, C. Jagadish","doi":"10.1109/COMMAD.2002.1237180","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237180","url":null,"abstract":"This paper demonstrates the improvement of kink-free operation in InGaAs/GaAs/AlGaAs high power, ridge waveguide laser diodes. Results show that when the thickness of the insulator layer is reduced below 200 nm and Ti/Pt/Au is used as the p-type metallization, significant absorption outside the ridge occurs as a result of the penetration of the vertical optical field into the absorptive metal layers. This effect can be used to introduce selective loss for the first order lateral mode. Hence, this study has shown that the kink-free operation can be improved by 30 to 50% in 980 nm emitting laser diodes when the thickness of the SiO/sub 2/ insulator is reduced to 50 to 75 nm.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"9 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121005936","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 : 2002-12-11DOI: 10.1109/COMMAD.2002.1237298
V. Coleman, P. Deenapanray, H. Tan, C. Jagadish
We have used deep level transient spectroscopy (DLTS) and capacitance-voltage (C-V) measurements to study impurity free disordering (IFD) of p-type GaAs epitaxial layers grown by metal-organic chemical vapour deposition (MOCVD). Disordering was achieved using either an SiO/sub 2/ or native oxide layer of the same thickness. Samples, including an uncapped layer for reference, were annealed at 900/spl deg/C for 30 s under an Ar ambient. Impurity-free disordering resulted in an increase in the free hole concentration, with the effect being most pronounced when using the SiO/sub 2/ capping layer. DLTS measurements revealed a corresponding increase in the concentrations of both Cu- and Zn-related deep levels in disordered epilayers. The results presented here will be discussed in terms of the atomic relocation processes that take place during the nonequilibrium injection of excess gallium vacancies into the disordered p-type epilayers.
{"title":"Atomic relocation of fast diffusers in impurity-free disordered p-type GaAs","authors":"V. Coleman, P. Deenapanray, H. Tan, C. Jagadish","doi":"10.1109/COMMAD.2002.1237298","DOIUrl":"https://doi.org/10.1109/COMMAD.2002.1237298","url":null,"abstract":"We have used deep level transient spectroscopy (DLTS) and capacitance-voltage (C-V) measurements to study impurity free disordering (IFD) of p-type GaAs epitaxial layers grown by metal-organic chemical vapour deposition (MOCVD). Disordering was achieved using either an SiO/sub 2/ or native oxide layer of the same thickness. Samples, including an uncapped layer for reference, were annealed at 900/spl deg/C for 30 s under an Ar ambient. Impurity-free disordering resulted in an increase in the free hole concentration, with the effect being most pronounced when using the SiO/sub 2/ capping layer. DLTS measurements revealed a corresponding increase in the concentrations of both Cu- and Zn-related deep levels in disordered epilayers. The results presented here will be discussed in terms of the atomic relocation processes that take place during the nonequilibrium injection of excess gallium vacancies into the disordered p-type epilayers.","PeriodicalId":129668,"journal":{"name":"2002 Conference on Optoelectronic and Microelectronic Materials and Devices. COMMAD 2002. Proceedings (Cat. No.02EX601)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133661314","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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