| 1. |
- Isheden, Christian, et al.
(författare)
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pMOSFETs with recessed and selectively regrown Si1-xGex source/drain junctions
- 2005
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Ingår i: Materials Science in Semiconductor Processing. - : Elsevier BV. - 1369-8001 .- 1873-4081. ; 8:1-3, s. 359-362
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Tidskriftsartikel (refereegranskat)abstract
- A new source/drain formation concept based on selective Si etching followed by selective regrowth of in situ B-doped Si(1-x)Ge(x)is presented. Both process steps are performed in the same reactor to preserve the gate oxide. Well-behaved transistors are demonstrated with a negligibly low gate-to-substrate leakage current.
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| 2. |
- Seger, Johan, et al.
(författare)
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Lateral encroachment of Ni-silicides in the source/drain regions on ultrathin silicon-on-insulator
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 86:25
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Tidskriftsartikel (refereegranskat)abstract
- Lateral growth of Ni silicide towards the channel region of metal-oxide-semiconductor transistors (MOSFETs) fabricated on ultrathin silicon-on-insulator (SOI) is characterized using SOI wafers with a 20-nm-thick surface Si layer. With a 10-nm-thick Ni film for silicide formation, p-channel MOSFETs displaying ordinary device characteristics with silicided p(+) source/drain regions were demonstrated. No lateral growth of NiSix under gate isolation spacers was found according to electron microscopy. When the Ni film was 20 nm thick, Schottky contact source/drain MOSFETs showing typical ambipolar characteristics were obtained. A severe lateral encroachment of NiSix into the channel region leading to an increased gate leakage was revealed, while no detectable voiding at the silicide front towards the Si channel was observed.
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| 3. |
- von Haartman, Martin, et al.
(författare)
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Low-frequency noise and Coulomb scattering in Si0.8Ge0.2 surface channel pMOSFETs with ALD Al2O3 gate dielectrics
- 2005
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 49:6, s. 907-914
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Tidskriftsartikel (refereegranskat)abstract
- Carrier mobility and low-frequency noise were investigated in Si0.8Ge0.2 surface channel pMOSFETs with ALD Al2O3 gate dielectrics. The devices were annealed in H2O Vapor, which reduced the negative charge in the gate dielectrics. The carrier mobility was characterized versus change in oxide charge, which allowed an estimation of the Coulomb scattering from the charge in the Al2O3. The low-frequency noise was measured between subthreshold and strong inversion conditions in the H2O annealed and the un-annealed devices. The combined number fluctuation and correlated mobility fluctuation noise model could successfully explain the observed 1/f noise. The mobility fluctuations were negatively correlated to the number fluctuations in the un-annealed devices, which contained a negative oxide charge. In the H2O annealed devices, on the other hand, a positive correlation could be observed. The maximum magnitude of the scattering parameter a was found to be around 1 X 10(4) Vs/C. The H2O annealing was used in this work as a non-destructive tool to modify the charge in the Al2O3, but it can also be a viable method to improve device performance by introducing/passivating charge.
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| 4. |
- von Haartman, Martin, et al.
(författare)
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Low-frequency noise in SiGe channel pMOSFETs on ultra-thin body SOI with Ni-silicided source/drain
- 2005
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Ingår i: Noise and Fluctuations. - : AIP. ; , s. 307-310
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Konferensbidrag (refereegranskat)abstract
- Thelow-frequency noise in buried SiGe channel pMOSFETs fabricated on ultra-thinbody silicon-on-insulator (SOI) substrates is investigated. The total thickness ofthe Si/SiGe/Si body structure, which is fully depleted (FD), is20 nm. The low-frequency noise properties are compared with FDSOI pMOSFETs with a 20 nm Si body. The effectof the Ni-silicide used in the Source/Drain were also studied,especially the case of Schottky-Barrier (SB) MOSFETs when the Ni-silicideis formed at the edges of the channel.
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| 5. |
- von Haartman, Martin, et al.
(författare)
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Noise in Si and SiGe MOSFETs with high-k gate dielectrics
- 2005
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Ingår i: Noise and Fluctuations. - : AIP. - 0735402671 ; , s. 225-230
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Konferensbidrag (refereegranskat)abstract
- This paper presents an overview of previous work and new insights on noise in Si-based MOSFETs with high-k gate dielectrics. Results for Al2O3, HfO2, HfAlOx and composite structures of these materials will be reported and compared. Incorporation of strained SiGe in high-k pMOSFETs in order to enhance hole mobility will be discussed in terms of low-frequency noise. A comparison will be made between devices with a surface Si channel, a surface SiGe channel and a buried SiGe channel. The influence of the gate electrode material and presence of a thin interfacial layer will be investigated. We will discuss noise modeling and highlight important differences compared to CMOS devices with standard gate oxide. Finally, we will discuss possible ways to reduce the 1/f noise in high-k MOSFETs. A noise reduction by a factor of two is obtained by forward biasing the substrate.
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| 6. |
- Östling, Mikael, et al.
(författare)
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Novel integration concepts for sige-based rf-MOSFETs
- 2005
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Ingår i: Proc. Electrochem. Soc.. ; , s. 270-284
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Konferensbidrag (refereegranskat)abstract
- An overview of critical integration issues for future generation rf-MOSFETs is presented. The process requirements and implementation of selective epitaxy for the source and drain regions is given. In-situ doping of highly boron doped recessed SiGe S/D is demonstrated. Channel region engineering is discussed and 50 nm strained SiGe pMOSFETs are demonstrated. Implementation of high-κ gate dielectrics is presented and device performance is demonstrated for surface channel MOSFETs with a gate stack based on ALD-formed HfO2/Al 2O3. Low frequency noise properties for those devices are analyzed. Contact metallization issues are critical for ultra scaled devices and here the implementation of NiSi on SiGe(C) regions as well as on ultra thin body SOI MOSFETs are presented. Finally, a spacer pattering technology using optical lithography to fabricate sub-50 nm high-frequency MOSFETs is demonstrated.
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