Analysis of Hydrogen Passivation Mechanisms in Poly-Si TFT’s by Employing R.F. Plasma

AbstractThe dominant pathways for hydrogen diffusion in poly-Si TFT’s are identified by analyzing the hydrogenation effect on the various device geometries. It is observed that the gate poly-Si thickness and channel width didn’t affect the hydrogenation. As the channel length was decreased down to 3 µm, threshold voltage was reduced and field effect mobility was increased significantly with hydrogeantion time. In the thick gate oxide (2000 Å, 4000 Å) poly-Si TFT’s, the device characteristics have been improved rapidly with hydrogenation time. The tail state density of thin gate oxide TFT wasn’t change by hydrgenation while that of thick gate oxide TFT was significantly reduced. Our experimental results may support the model that hydrogen atoms diffuse into the bulk of the active channel layer through the gate oxide and passivate the grain boundary and intragranular defects limitedly by gate oxide area.

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Characterization of Ba-Introduced Thin Gate Oxide on 4H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.963.451 ◽

2019 ◽

Vol 963 ◽

pp. 451-455 ◽

Cited By ~ 1

Author(s):

Kosuke Muraoka ◽

Seiji Ishikawa ◽

Hiroshi Sezaki ◽

Tomonori Maeda ◽

Shinichiro Kuroki

Keyword(s):

Oxygen Concentration ◽

Barrier Layer ◽

Gate Oxide ◽

Interface State ◽

State Density ◽

Conduction Band Edge ◽

Low Oxygen ◽

Barrier Layer Thickness ◽

Thick Barrier ◽

Thin Gate Oxide

A thickness of Ba-introduced gate oxide was controlled with the oxygen concentration and a barrier layer thickness at a post-deposition annealing. The oxidation rate becomes slower with the low oxygen concentration and the thick barrier layer, and the thin oxide of 12 nm was realized with O2 5% and 9 nm of the barrier layer. This Ba-introduced thin gate oxide resulted in the field effect mobility of 13 cm2/Vs and the interface state density of 2×1011 cm-2eV-1 at 0.25 eV below the conduction band edge of 4H-SiC.

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Electrical Properties of High-K LaLuO3 Gate Oxide for SOI MOSFETs

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.276.87 ◽

2011 ◽

Vol 276 ◽

pp. 87-93

Author(s):

Y.Y. Gomeniuk ◽

Y.V. Gomeniuk ◽

A. Nazarov ◽

P.K. Hurley ◽

Karim Cherkaoui ◽

...

Keyword(s):

Electrical Characterization ◽

Gate Oxide ◽

Interface State ◽

Channel Length ◽

State Density ◽

Interface State Density ◽

Mos Capacitors ◽

Channel Mobility ◽

Threshold Voltages

The paper presents the results of electrical characterization of MOS capacitors and SOI MOSFETs with novel high-κ LaLuO3 dielectric as a gate oxide. The energy distribution of interface state density at LaLuO3/Si interface is presented and typical maxima of 1.2×1011 eV–1cm–2 was found at about 0.25 eV from the silicon valence band. The output and transfer characteristics of the n- and p-MOSFET (channel length and width were 1 µm and 50 µm, respectively) are presented. The front channel mobility appeared to be 126 cm2V–1s–1 and 70 cm2V–1s–1 for n- and p-MOSFET, respectively. The front channel threshold voltages as well as the density of states at the back interface are presented.

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Measurements of Grain Boundary Trap Density and Hydrogen Diffusivity in Polycrystalline Silicon Fet's

MRS Proceedings ◽

10.1557/proc-182-341 ◽

1990 ◽

Vol 182 ◽

Cited By ~ 6

Author(s):

Chad B. Moore ◽

Dieter G. Ast

Keyword(s):

Grain Boundary ◽

Polycrystalline Silicon ◽

Hydrogen Diffusion ◽

State Density ◽

Trap Density ◽

Hydrogen Diffusivity ◽

Trap State ◽

Polycrystalline Silicon Films ◽

Hydrogenation Time ◽

Deposited Films

AbstractHydrogen diffusion in as-deposited and in oxidation-annealed polycrystalline silicon films was investigated using n-type accumulation-mode MOSFET's. The diffusion was studied by measuring the reduction in the grain boundary trap density with hydrogenation time. The number of traps in fully hydrogenated as-deposited films fell to about 45% of the initial trap state density and fell to about 20% in the oxidized-annealed films. Concurrently, the mobility increased about 95 % to 5cm2/Vs in the as-deposited films and by about 55 % to 25 cm2/Vs in the oxidized polysilicon devices. The effective preexponential diffusion coefficient and activation energy for hydrogen diffusion in the two different films were Do= 5.4×10−10 cm2/s and EA= 0.37 eV for the as-deposited polysilicon and Do=2.1×10−10 cm2/s and EA= 0.36 eV for the oxidized polysilicon.

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Low temperature operation of ultra-thin gate oxide sub-0.1 μm MOSFETs

Journal de Physique IV (Proceedings) ◽

10.1051/jp420020036 ◽

2002 ◽

Vol 12 (3) ◽

pp. 57-60 ◽

Cited By ~ 2

Author(s):

B. Cretu ◽

F. Balestra ◽

G. Ghibaudo ◽

G. Guégan

Keyword(s):

Low Temperature ◽

Gate Oxide ◽

Thin Gate Oxide

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Magnetic Volume Effect of Hydrogen Diffusion in Palladium

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.310.29 ◽

2020 ◽

Vol 310 ◽

pp. 29-33

Author(s):

Sarantuya Nasantogtokh ◽

Xin Cui ◽

Zhi Ping Wang

Keyword(s):

Transition Metal ◽

Density Of States ◽

Density Functional ◽

Hydrogen Diffusion ◽

Magnetic Moments ◽

Interstitial Site ◽

Volume Effect ◽

Face Centered Cubic ◽

Hydrogen Atoms ◽

Octahedral Interstitial Site

The electronic and magnetic properties of palladium hydrogen are investigated using first-principles spin-polarized density functional theory. By studying the magnetic moments and electronic structures of hydrogen atoms diffusing in face-centered cubic structure of transition metal Pd, we found that the results of magnetic moments are exactly the same in the two direct octahedral interstitial site-octahedral interstitial site diffusion paths-i.e. the magnetic moments are the largest in the octahedral interstitial site, and the magnetic moments are the lowest in saddle point positions. We also studied on the density of states of some special points, with the result that the density of states near the Fermi level is mainly contributed by 4d electrons of Pd and the change of magnetic moments with the cell volume in the unit cell of transition metal Pd with a hydrogen atom.

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Enhanced ion implantation charging damage on thin gate oxide due to photoresist

Proceedings of 11th International Conference on Ion Implantation Technology ◽

10.1109/iit.1996.586136 ◽

2002 ◽

Cited By ~ 1

Author(s):

Donggun Park ◽

Chenming Hu

Keyword(s):

Ion Implantation ◽

Gate Oxide ◽

Thin Gate Oxide

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Band Tailing and Transport in a-SiGe:H-Alloys

MRS Proceedings ◽

10.1557/proc-149-485 ◽

1989 ◽

Vol 149 ◽

Cited By ~ 18

Author(s):

G. H. Bauer ◽

C. E. Nebel ◽

M. B. Schubert ◽

G. Schumm

Keyword(s):

Raman Scattering ◽

Valence Band ◽

State Density ◽

Conduction Band Edge ◽

Compound Structure ◽

Tail State ◽

Photocurrent Spectroscopy ◽

Transport Studies ◽

Small X ◽

Band Tailing

ABSTRACTOptical and transport studies of both cb- and vb-tail states in a-Si1−xGex:H such as subband absorption (PDS), instationary photocurrent experiments (TOF, PTS) for electrons and holes, Modulated Photocurrent Spectroscopy (MPS), and Raman scattering have been performed. The main consequences of Ge-alloying into the a-Si:H network are i) an increase in cb-tail state density at the conduction band edge and in the exponential cb- tail even for small x (O<x<0.3), accompanied by ii) a rise in deep cb-tail and midgap states which to some extent can be reduced by appropriate deposition methods; iii) at the valence band side up to x≈0.3 the tail seems not to be affected at all and for 0.3<x<0.9 the vb-tail obviously can be kept similar to that of a-Si:H (Evo≈(50–60) meV). Halfwidths of Raman TO-like modes point to the existence of a rigid Si-network in O<x<0.3 in which Ge is incorporated and to a transition at x>0.35 into a Si-Ge compound structure with maximum disorder at x≈0.5.

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