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- Ouacha, H., et al.
(författare)
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Comparison between the noise properties of PtSi/p-Si1-xGex and Pt/p-Si1-xGex Schottky contacts prepared by co-sputtering and thermal reaction
- 2001
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 16:4, s. 255-259
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Tidskriftsartikel (refereegranskat)abstract
- The noise properties of Pt/p-Si1-xGex and PtSi/p-Si1-xGex (x = 0.14) Schottky contacts have been studied. The silicide layer PtSi was formed by thermal reaction (TR) of Pt with a silicon substrate and by co-sputtering (CS) of Pt and Si onto the strained Si1-xGex layer. The noise measurements were performed at temperature T = 77 K over the frequency range 10-104 Hz. Higher noise level was observed in the annealed diode Pt/p-Si1-xGex. In both diodes, the noise was found to exhibit 1/f behaviour and was attributed to fluctuations of the generation-recombination current at the interface states. The results reveal significant reductions in the total noise by 70%, and the interface state density Nit by three orders of magnitude when the silicide is formed by the CS process.
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| 2. |
- Ouacha, H, et al.
(författare)
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Impact of plasma etching on the noise performance of Ti/p-Si and Ti/p-Si1-xGex Schottky contacts
- 2000
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Ingår i: Journal of Applied Physics. - 0021-8979 .- 1089-7550. ; 87:8, s. 3858-3863
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Tidskriftsartikel (refereegranskat)abstract
- The effect of plasma etching on the noise properties of Ti/p-Si and Ti/p-Si1-xGex (with x=0.05) Schottky junctions has been investigated. The noise measurements were performed over a temperature range of 77-300 K at frequencies of 10-100 kHz. The main noise source observed in these diodes during argon plasma sputter etching was attributed to the generation-recombination noise. From the analysis of the noise data, we have determined the interface state density and evaluated the introduced damage. The results indicate two optimum operating temperatures where low-noise level can be achieved. Furthermore, the activation energies of trap levels have been extracted by using noise spectroscopy (NS) and compared with those measured by deep-level transient spectroscopy (DLTS). We found two additional trap states using NS not detected by DLTS measurements. Finally, a noise comparison between Ti/p-Si and Ir/p-Si fabricated on an unetched substrate has been made. (C) 2000 American Institute of Physics. [S0021-8979(00)00608-3].
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| 3. |
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| 4. |
- Malmqvist, R., et al.
(författare)
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Reconfigurable RF Circuits and RF-MEMS
- 2012
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Ingår i: Microwave and Millimeter Wave Circuits and Systems. - : John Wiley & Sons. - 9781119944942 ; , s. 325-356
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Bokkapitel (refereegranskat)abstract
- The twelfth chapter, Reconfigurable RF Circuits and RF-MEMS, was contributed by Robert Malmqvist from Swedish Defence Research Agency (FOI) and Uppsala University, Sweden, Aziz Ouacha from FOI, Sweden, Mehmet Kaynak from IHP GmbH, Frankfurt (Oder), Germany, Naveed Ahsan Linköping University, Sweden, and Joachim Oberhammer from KTH Royal Institute of Technology, Stockholm, Sweden. While most of today's RF circuits are designed for a specific (fixed) function and frequency range, a much higher degree of flexibility would be possible using highly reconfigurable circuit implementations and front-ends architectures. This chapter presents examples of reconfigurable RF circuits that have been realised using either fully transistor based solutions or by employing RF MicroElectroMechanical Systems (RF-MEMS). First a novel approach for implementing reconfigurable circuitry based on the concept of Programmable Microwave Function Arrays (PROMFA) is presented. Various reconfigurable circuit designs based on the emergence of high performance RF-MEMS switches being developed in GaAs, GaN and SiGe RFIC/MMIC process technologies are then reviewed. In the final section, an overview of state-of-the-art RF-MEMS based phase shifter designs intended for electronic beam-steering antennas and phased array systems is presented.
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