| 1. |
- Esteve, Romain, et al.
(författare)
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Advanced oxidation process combining oxide deposition and short postoxidation step for N-type 3C- and 4H-SiC
- 2009
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 106:4
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Tidskriftsartikel (refereegranskat)abstract
- The electrical properties of oxides fabricated on n-type 3C-SiC (001) and 4H-SiC (0001) epilayers using an advanced oxidation process combining plasma enhanced deposition and rapid postoxidation steps have been investigated. Three gas atmospheres have been studied for the postoxidation steps: N2O, dry, and wet oxygen (H2O). In comparison, additional oxides using postannealing in pure N-2 have been fabricated. The implementation of wet oxygen resulted. in a significant decrease in the interface traps density, in a reduction of oxide fixed charges and in the increased breakdown field in the case of 3C-SiC. In the case of 4H-SiC the postoxidation in N2O is a superior postprocessing step.
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| 2. |
- Esteve, Romain, et al.
(författare)
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Comparative study of thermally grown oxides on n-type free standing 3C-SiC (001)
- 2009
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 106:4
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Tidskriftsartikel (refereegranskat)abstract
- Alternative ways to improve the oxidation process of free standing 3C-SiC (001) are developed and tested with the aim to reduce the fixed and mobile charges in the oxide and at the SiO2/3C-SiC interface. The postoxidation annealing step in wet oxygen (O-2+H-2) is demonstrated to be beneficial for n-type 3C-SiC metal-oxide-semi conductor capacitors resulting in significant reduction in flat band voltage shift, effective oxide charge density, and density of interface traps. The inefficiency of nitridation for the improvement of the oxide quality on 3C-SiC is discussed.
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| 3. |
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| 4. |
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| 5. |
- Forsen, E, et al.
(författare)
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Ultrasensitive mass sensor fully integrated with complementary metal-oxide-semiconductor circuitry
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 87:4
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Tidskriftsartikel (refereegranskat)abstract
- Nanomechanical resonators have been monolithically integrated on preprocessed complementary metal-oxide-semiconductor (CMOS) chips. Fabricated resonator systems have been designed to have resonance frequencies up to 1.5 MHz. The systems have been characterized in ambient air and vacuum conditions and display ultrasensitive mass detection in air. A mass sensitivity of 4 ag/Hz has been determined in air by placing a single glycerine drop, having a measured weight of 57 fg, at the apex of a cantilever and subsequently measuring a frequency shift of 14.8 kHz. CMOS integration enables electrostatic excitation, capacitive detection, and amplification of the resonance signal directly on the chip.
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| 6. |
- Ghatnekar-Nilsson, Sara, et al.
(författare)
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Resonators with integrated CMOS circuitry for mass sensing applications, fabricated by electron beam lithography
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16:1, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- A resonator system has been fabricated directly on a pre-processed CMOS chip. The system is to be used for high sensitivity mass sensing applications in air and vacuum. The resonator system, corresponding of a cantilever and structures for electrostatic actuation and capacitive read-out, have been defined by electron beam lithography on top of a charge and radiation sensitive CMOS layer in predefined areas as a post-process step. This has been accomplished without affecting the electronic properties of the pre-processed CMOS circuits. The subsequent etching steps to fully release the cantilevers have been obtained without stiction of the cantilevers to the substrate. Cantilevers are driven at their mechanical resonance in a lateral mode, and the frequency is monitored by capacitive read-out on the chip. CMOS integration enables signal detection directly on the chip, which radically decreases the parasitic capacitances. Consequently, low-noise electrical measurements with a very high mass sensitivity are obtained. Fabricated resonator systems were characterized to have resonance frequencies of approximately 1.49 MHz, which is in good agreement with a theoretical estimation of 1.41 MHz. The theoretical mass resolution, partial derivativem/partial derivativef, is approximately 17 ag Hz(-1) using a Young modulus value of 160 GPa.
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| 7. |
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| 8. |
- Peralvarez-Marin, Alex, et al.
(författare)
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Inter-helical hydrogen bonds are essential elements for intra-protein signal transduction : The role of Asp115 in bacteriorhodopsin transport function
- 2007
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 368:3, s. 666-676
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Tidskriftsartikel (refereegranskat)abstract
- The behavior of the D115A mutant was analyzed by time-resolved UV-Vis and Fourier transformed infrared (FTIR) spectroscopies, aiming to clarify the role of Asp115 in the intra-protein signal transcluctions occurring during the bacteriorhodopsin photocycle. UV-Vis data on the D115A mutant show severely desynchronized photocycle kinetics. FTIR data show a poor transmission of the retinal isomerization to the chromoprotein, evidenced by strongly attenuated helical changes (amide 1), the remarkable absence of environment alterations and protonation/deprotonation events related to Asp96 and direct Schiff base (SB) protonation form the bulk. This argues for the interactions of Asp115 with Leu87 (via water molecule) and Thr90 as key elements for the effective and vectorial proton path between Asp96 and the SB in the cytoplasmic half of bacteriorhodopsin. The results strongly suggest the presence of a regulation motif enclosed in helices C and D (Thr90-Pro91/Asp115) which drives properly the dynamics of helix C through a set of interactions. It also supports the idea that intra-helical hydrogen bonding clusters in the buried regions of transmembrane proteins can be potential elements in intra-protein signal transduction.
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