| 1. |
- Buyanova, Irina, 1960-, et al.
(författare)
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Intrinsic modulation doping in InP-based structures : properties relevant to device applications
- 1999
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Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 201-202, s. 786-789
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Tidskriftsartikel (refereegranskat)abstract
- In this work we study device-relevant issues, such as doping efficiency and thermal stability, of recently proposed intrinsic modulation doping approach where intrinsic defects (PIn antisites) are used as a carrier source instead of impurity dopants. The InP/InGaAs heterostructure designed to resemble high electron mobility transistor (HEMT) structures, where all the layers were grown at a normal growth temperature 480°C except for the top InP layer which was grown at 265°C, was used as a prototype device. A comparison between the intrinsically doped structure with extrinsically doped HEMTs, which have an identical design except that the top InP layer was instead Si-doped and was grown at 480°C, reveals a high efficiency of the intrinsic doping. The thermal stability of the intrinsically doped HEMT is examined by annealing at temperatures 400-500°C relevant to possible processing steps needed in device fabrication. The observed severe reduction of the carrier concentration after annealing performed without phosphorous gas protection is attributed to the known instability of an InP surface at T>400°C. Thermal stability of the intrinsically doped HEMT is shown to be improved by using an InP cap layer grown at 480°C.
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| 2. |
- Buyanova, Irina, 1960-, et al.
(författare)
-
Thermal stability and doping efficiency of intrinsic modulation doping in InP-based structures
- 1999
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 75:12, s. 1733-
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Tidskriftsartikel (refereegranskat)abstract
- Doping efficiency and thermal stability of intrinsic modulation doping in InP/InGaAs heterostructures, where intrinsic defects (PInantisites) are used as an electron source, are investigated. A high efficiency of the intrinsic doping is demonstrated from a comparison between the intrinsically doped and conventional extrinsically doped structures. The thermal stability of the intrinsically doped heterostructures is shown to be largely affected by the thermal stability of the InP surface.
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| 3. |
- Chen, Weimin, 1959-, et al.
(författare)
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Transport properties of intrinsically and extrinsically modulation doped InP/InGaAs heterostructures
- 1999
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Ingår i: Physica Scripta. - 0031-8949 .- 1402-4896. ; T79, s. 103-105
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Tidskriftsartikel (refereegranskat)abstract
- Transport properties in a new type of modulation doped InP/InGaAs systems, where the n-type doping is provided by intrinsic PIn-antisite defects rather than foreign impurities, are studied by Shubnikov-de-Haas (SdH) oscillations and low-field Hall effect measurements. A close comparison of transport properties is made between these intrinsically modulation doped structures with extrinsically doped structures, with the emphasis on two of the most important physical processes i.e. doping efficiency and scattering mechanism. It is found that the efficiency of the intrinsic modulation doping is at least as high as the extrinsic modulation doping. The mobilities of the two dimensional electron gas (2DEG) derived from Hall and SdH measurements are shown to be higher in the intrinsically doped structures as compared to the extrinsically doped structures. This is attributed to a reduced scattering of the 2DEG by the remote parent dopants, due to e.g. an increased screening of the scattering potential by the excess free electrons present in the intrinsic doping region due to auto-ionization of the PIn antisite.
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