Pub Date : 1998-12-14DOI: 10.1109/COMMAD.1998.791587
G. Sberveglieri, C. Baratto, E. Comini, G. Faglia, P. Nelli, L. Dori
In this paper we review the electrical properties of semiconducting layers based on metal oxide thin films used for monitoring environmental gases and examine some innovative technique to increase the sensor selectivity towards particular gases (pulsed temperature, use of UV irradiation). The sensing layers are deposited onto a micromachined silicon substrate, which is characterized by low power consumption and allowed the interface with the process electronics.
{"title":"Recent progress on gas sensors based on semiconducting thin films","authors":"G. Sberveglieri, C. Baratto, E. Comini, G. Faglia, P. Nelli, L. Dori","doi":"10.1109/COMMAD.1998.791587","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791587","url":null,"abstract":"In this paper we review the electrical properties of semiconducting layers based on metal oxide thin films used for monitoring environmental gases and examine some innovative technique to increase the sensor selectivity towards particular gases (pulsed temperature, use of UV irradiation). The sensing layers are deposited onto a micromachined silicon substrate, which is characterized by low power consumption and allowed the interface with the process electronics.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115906304","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791584
S. Cristoloveanu
SOI technologies are reviewed in terms of wafer fabrication, device properties, and development challenges. The basic SOI assets for the microelectronics future are discussed and compared to those of bulk-silicon technology. There are two types of SOI MOSFETs-fully-depleted and partially-depleted-each governed by special mechanisms which will be briefly addressed.
{"title":"Silicon on insulator technology, devices, and challenges","authors":"S. Cristoloveanu","doi":"10.1109/COMMAD.1998.791584","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791584","url":null,"abstract":"SOI technologies are reviewed in terms of wafer fabrication, device properties, and development challenges. The basic SOI assets for the microelectronics future are discussed and compared to those of bulk-silicon technology. There are two types of SOI MOSFETs-fully-depleted and partially-depleted-each governed by special mechanisms which will be briefly addressed.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123001521","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791665
M. H. Rais, C. Musca, J. Dell, J. Antoszewski, B. Nener
This paper presents a study on the temperature and bias dependence of 1/f noise for mid-wavelength infrared (MWIR) HgCdTe n-on-p photodiodes fabricated on vacancy doped p-type LPE grown epilayers. The low frequency noise spectrum is fitted to a theoretical model to determine the dark current mechanism responsible for the 1/f noise component. At temperatures above 130 K the 1/f noise is dominated by the diffusion current component, and the temperature dependence in this regime gives an activation energy of 0.73E/sub g/. The Hooge parameter obtained from the model increased monotonically from 1.7/spl times/10/sup -4/ to 2.25/spl times/10/sup -3/ as the temperature was varied from 130 K to 180 K.
{"title":"Low frequency noise in HgCdTe 3-5 micron IR photovoltaic detectors at elevated temperatures","authors":"M. H. Rais, C. Musca, J. Dell, J. Antoszewski, B. Nener","doi":"10.1109/COMMAD.1998.791665","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791665","url":null,"abstract":"This paper presents a study on the temperature and bias dependence of 1/f noise for mid-wavelength infrared (MWIR) HgCdTe n-on-p photodiodes fabricated on vacancy doped p-type LPE grown epilayers. The low frequency noise spectrum is fitted to a theoretical model to determine the dark current mechanism responsible for the 1/f noise component. At temperatures above 130 K the 1/f noise is dominated by the diffusion current component, and the temperature dependence in this regime gives an activation energy of 0.73E/sub g/. The Hooge parameter obtained from the model increased monotonically from 1.7/spl times/10/sup -4/ to 2.25/spl times/10/sup -3/ as the temperature was varied from 130 K to 180 K.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127758651","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791622
R. Sani, M. Barmawi, P. Arifin, Sugianto
Thin films of GaN on SI-GaAs and SnO/sub 2/ substrates were successfully grown by Microwave Plasma enhanced MOCVD at substrate temperatures in the vicinity of 650/spl deg/C. These temperatures are substantially lower than the growth temperature of GaN using a conventional MOCVD, which is in excess of 1000/spl deg/C. Trimethylgallium and nitrogen were used as precursors. A plasma applicator was used to create the nitrogen plasma, which was delivered from the cavity to the place near the substrate hearer using a quartz tube. X-ray diffraction measurements were revealed that the grown layer is a hexagonal structure. A Hall-van der Pauw technique was employed to measure the electrical properties. As grown material, room temperature resistivity, mobility, and carrier concentration are 36 /spl Omega//spl middot/cm, 73 cm/sup 2//V/spl middot/s, and 4.6/spl times/10/sup 15/ cm/sup -3/ respectively. Photoluminescence measurements were performed using a He-Cd laser emitting at 325 nm at different the temperatures. Luminescence, centered at 2.9 eV were clearly observed. Meanwhile the UV absorption spectrum showed a band-gap of around 3.4 eV.
{"title":"Growth of GaN by microwave plasma enhanced MOCVD","authors":"R. Sani, M. Barmawi, P. Arifin, Sugianto","doi":"10.1109/COMMAD.1998.791622","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791622","url":null,"abstract":"Thin films of GaN on SI-GaAs and SnO/sub 2/ substrates were successfully grown by Microwave Plasma enhanced MOCVD at substrate temperatures in the vicinity of 650/spl deg/C. These temperatures are substantially lower than the growth temperature of GaN using a conventional MOCVD, which is in excess of 1000/spl deg/C. Trimethylgallium and nitrogen were used as precursors. A plasma applicator was used to create the nitrogen plasma, which was delivered from the cavity to the place near the substrate hearer using a quartz tube. X-ray diffraction measurements were revealed that the grown layer is a hexagonal structure. A Hall-van der Pauw technique was employed to measure the electrical properties. As grown material, room temperature resistivity, mobility, and carrier concentration are 36 /spl Omega//spl middot/cm, 73 cm/sup 2//V/spl middot/s, and 4.6/spl times/10/sup 15/ cm/sup -3/ respectively. Photoluminescence measurements were performed using a He-Cd laser emitting at 325 nm at different the temperatures. Luminescence, centered at 2.9 eV were clearly observed. Meanwhile the UV absorption spectrum showed a band-gap of around 3.4 eV.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124625635","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791662
J. Zou, D. Cai, D. Cockayne, S. Yuan, C. Jagadish
In this paper, we demonstrate the application of thickness fringe imaging technique to determine the quantum well profile in an interdiffused GaAsAl/GaAs quantum well heterostructure.
{"title":"TEM measurement of Al profiles in interdiffused GaAs/AlGaAs quantum-wells","authors":"J. Zou, D. Cai, D. Cockayne, S. Yuan, C. Jagadish","doi":"10.1109/COMMAD.1998.791662","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791662","url":null,"abstract":"In this paper, we demonstrate the application of thickness fringe imaging technique to determine the quantum well profile in an interdiffused GaAsAl/GaAs quantum well heterostructure.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121056301","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791583
O. Wadu
Ultrafast optoelectronic devices are crucial for fulfilling the future requirement of network throughput to enter the 1 Tb/s to 10 Tb/s range. A variety of ultrafast phenomena in InP-based semiconductors are attractive for developing such new optoelectronic devices. This paper discusses the requirements of ultrafast optical communication and signal-processing systems and devices necessary for them. Recent advances in the development of ultrafast semiconductor-based optoelectronic devices, such as ultrashort pulse lasers and ultrafast all-optical switches, are described.
{"title":"Femtosecond semiconductor optoelectronic devices for ultrahigh throughput optical communications systems","authors":"O. Wadu","doi":"10.1109/COMMAD.1998.791583","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791583","url":null,"abstract":"Ultrafast optoelectronic devices are crucial for fulfilling the future requirement of network throughput to enter the 1 Tb/s to 10 Tb/s range. A variety of ultrafast phenomena in InP-based semiconductors are attractive for developing such new optoelectronic devices. This paper discusses the requirements of ultrafast optical communication and signal-processing systems and devices necessary for them. Recent advances in the development of ultrafast semiconductor-based optoelectronic devices, such as ultrashort pulse lasers and ultrafast all-optical switches, are described.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122010115","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791608
W. Qu, W. Wlodarski, R. Green, M. Austin, K. Galatsis
Two types of bi-functional film sensors have been developed for environmental applications. The first sensing device is based on n-type semiconducting metal oxide WO/sub 3/ and is fabricated using thin-film surface microfabrication technology. It utilises gas chemisorption at elevated temperatures higher than 300/spl deg/C as well as water physisorption on grain surfaces at temperatures lower then 150/spl deg/C. Both humidity and particular pollution gases such as ozone, NH/sub 3/ and NO/sub 2/ can be detected with high sensitivity and selectivity. The Pt-film heater at the back side of the sensor serves also as a thermometer. The other sensor is composed of Cr/sup 3+/ doped porous perovskite Ba/sub 1-x/Sr/sub x/TiO/sub 3/ (x=0-1) and is fabricated using thick-film technology. It exhibits a change in dielectric constant with respect to temperature variations, while the electrical resistance is a function of humidity. Hence, temperature and humidity can be simultaneously and independently detected by measuring the sensor capacitance and the sensor resistance. Crosstalk between both sensing measurands is negligible.
{"title":"Novel bi-functional film ceramic sensors for environmental applications","authors":"W. Qu, W. Wlodarski, R. Green, M. Austin, K. Galatsis","doi":"10.1109/COMMAD.1998.791608","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791608","url":null,"abstract":"Two types of bi-functional film sensors have been developed for environmental applications. The first sensing device is based on n-type semiconducting metal oxide WO/sub 3/ and is fabricated using thin-film surface microfabrication technology. It utilises gas chemisorption at elevated temperatures higher than 300/spl deg/C as well as water physisorption on grain surfaces at temperatures lower then 150/spl deg/C. Both humidity and particular pollution gases such as ozone, NH/sub 3/ and NO/sub 2/ can be detected with high sensitivity and selectivity. The Pt-film heater at the back side of the sensor serves also as a thermometer. The other sensor is composed of Cr/sup 3+/ doped porous perovskite Ba/sub 1-x/Sr/sub x/TiO/sub 3/ (x=0-1) and is fabricated using thick-film technology. It exhibits a change in dielectric constant with respect to temperature variations, while the electrical resistance is a function of humidity. Hence, temperature and humidity can be simultaneously and independently detected by measuring the sensor capacitance and the sensor resistance. Crosstalk between both sensing measurands is negligible.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122464640","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791703
Xingquan Liu, Wei Lu, Xiaoshuang Chen, S. Shen, H. Tan, S. Yuan, C. Jagadish, M. Johnston, L. Dao, M. Gal, J. Zou, D. Cockayne
Selective implantation induced intermixing was used to separate the spectral response of quantum wire from that of the quantum wells in V-grooved quantum wire structure. Photoluminescence (PL) measurement was accomplished to show the separation of the spectral response.
{"title":"Application of selective implantation induced intermixing on V-grooved AlGaAs/GaAs coupled quantum wire","authors":"Xingquan Liu, Wei Lu, Xiaoshuang Chen, S. Shen, H. Tan, S. Yuan, C. Jagadish, M. Johnston, L. Dao, M. Gal, J. Zou, D. Cockayne","doi":"10.1109/COMMAD.1998.791703","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791703","url":null,"abstract":"Selective implantation induced intermixing was used to separate the spectral response of quantum wire from that of the quantum wells in V-grooved quantum wire structure. Photoluminescence (PL) measurement was accomplished to show the separation of the spectral response.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125148151","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791632
W. Liu, J.Y. Chen, W.C. Wang, S. Feng, K. Yu, J. Yan
An InGaP/GaAs heterojunction bipolar transistor (HBT) with an 50 /spl Aring/ undoped spacer and /spl delta/-doping sheet at base-emitter heterointerface is fabricated and studied. A common-emitter current gain of 280 and an offset voltage as small as 55 mV are obtained, respectively. This results show that high current gain and low offset voltage can be attained simultaneously without the passivation of emitter-base junction. From the experimental results, it shows that the potential spike is indeed reduced by the employment of an /spl delta/-doped layer and spacer simultaneously. On the other hand, theoretical consideration also shows that the potential spike is removed by inserting a /spl delta/-doping sheet between the emitter-base heterointerface.
{"title":"Design consideration of emitter-base junction structure for InGaP/GaAs heterojunction bipolar transistor","authors":"W. Liu, J.Y. Chen, W.C. Wang, S. Feng, K. Yu, J. Yan","doi":"10.1109/COMMAD.1998.791632","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791632","url":null,"abstract":"An InGaP/GaAs heterojunction bipolar transistor (HBT) with an 50 /spl Aring/ undoped spacer and /spl delta/-doping sheet at base-emitter heterointerface is fabricated and studied. A common-emitter current gain of 280 and an offset voltage as small as 55 mV are obtained, respectively. This results show that high current gain and low offset voltage can be attained simultaneously without the passivation of emitter-base junction. From the experimental results, it shows that the potential spike is indeed reduced by the employment of an /spl delta/-doped layer and spacer simultaneously. On the other hand, theoretical consideration also shows that the potential spike is removed by inserting a /spl delta/-doping sheet between the emitter-base heterointerface.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128467453","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 : 1998-12-14DOI: 10.1109/COMMAD.1998.791666
K. Galatsis, W. Qu, W. Wlodarski
This short paper describes a new idea for humidity measurement using QCM (Quartz Crystal Microbalance) devices. It is based on an etching approach which produces micropores into the electrodes of a QCM, instead of the common approach of coating the electrodes with hygroscopic materials. The electrodes are etched wet-chemically using buffered king water (NHO/sub 3/:HCl=1:3). The electrode surface becomes rough, resulting in a large surface area for water adsorption. Photolithographic etching using a plasma will be the next research stage, this will eliminate the generation of a randomly dented surface, hence providing a uniform porous structure. Fabrication and results of preliminary measurement are described in this paper.
{"title":"Quartz crystal microbalance humidity sensor with porous electrodes","authors":"K. Galatsis, W. Qu, W. Wlodarski","doi":"10.1109/COMMAD.1998.791666","DOIUrl":"https://doi.org/10.1109/COMMAD.1998.791666","url":null,"abstract":"This short paper describes a new idea for humidity measurement using QCM (Quartz Crystal Microbalance) devices. It is based on an etching approach which produces micropores into the electrodes of a QCM, instead of the common approach of coating the electrodes with hygroscopic materials. The electrodes are etched wet-chemically using buffered king water (NHO/sub 3/:HCl=1:3). The electrode surface becomes rough, resulting in a large surface area for water adsorption. Photolithographic etching using a plasma will be the next research stage, this will eliminate the generation of a randomly dented surface, hence providing a uniform porous structure. Fabrication and results of preliminary measurement are described in this paper.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127336503","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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