Optical Spectroscopy of the Charge Accumulation Layer in Mis Structures with Polymeric Insulator and Semiconductor Layers

1989 ◽  
Vol 173 ◽  
Author(s):  
J. H. Burroughes ◽  
R. H. Friend
Keyword(s):  
Silicon Dioxide ◽  
Optical Measurements ◽  
Charge Storage ◽  
Electronic Excitations ◽  
Charge Accumulation ◽  
Metal Insulator ◽  
Accumulation Layer ◽  
Precursor Route ◽  
Insulator Layers ◽  
Mis Structures

ABSTRACTMetal-Insulator-Semiconductor (MIS) and MISFET structures constructed with polyacetylene prepared by the Durham precursor route provide convenient systems for the investigation of charge storage and transport in this polymer. The charge accumulation layer is particularly easy to form, and is of particular interest because charge is introduced into the polymer without compensation by chemical dopants. Charge is stored in soliton-like excitations of the chain, and we are able to characterise these from optical measurements of their electronic excitations. We find that the nature of the soliton-like states is very sensitive to the structure of the polyacetylene at the interface between the insulator and polyacetylene, and we report here the properties of devices formed with various organic polymers as the insulator layers which we contrast with those formed with silicon dioxide.

Tunneling Current Through MIS Structures With Ultra-Thin Insulators

1996 ◽  
Vol 428 ◽  
Author(s):  
H. Fujioka ◽  
H.-J. Wann ◽  
D.-G. Park ◽  
Y.-C. King ◽  
Y.-F. Chyan ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Tunneling Current ◽  
Silicon Oxynitride ◽  
Leakage Currents ◽  
Metal Insulator ◽  
Minute Amount ◽  
Semiconductor Structures ◽  
Direct Tunneling ◽  
Tunneling Mechanism ◽  
Mis Structures

AbstractLeakage currents through MIS (Metal Insulator Semiconductor) structures with several ultra-thin (14–30Å) insulators (silicon dioxide, silicon oxynitride, and silicon nitride) have been investigated. The leakage currents through both dioxide and oxynitride films sandwiched between n-type poly-Si gates and n-type substrates can be well fitted by the equation for the electron direct tunneling mechanism using the same effective mass and barrier height. This result indicates that incorporation of a minute amount of nitrogen atoms does not seriously affect the basic electrical properties of the oxide films. Leakage currents through ultra-thin nitride can te also fitted with the equation for the direct tunneling mechanism without assuming any extra conduction mechanisms such as hopping through defects.

Quantum oscillations in the high- T c cuprates

2011 ◽  
Vol 369 (1941) ◽  
pp. 1687-1711 ◽  
Author(s):  
Suchitra E. Sebastian ◽  
Neil Harrison ◽  
Gilbert G. Lonzarich
Keyword(s):  
Fermi Surface ◽  
Cuprate Superconductors ◽  
Low Energy ◽  
Quantum Oscillation ◽  
Electronic Excitations ◽  
Close Correspondence ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Quantum Oscillations ◽  
Underdoped Cuprates

We review recent progress in the study of quantum oscillations as a tool for uniquely probing low-energy electronic excitations in high- T c cuprate superconductors. Quantum oscillations in the underdoped cuprates reveal that a close correspondence with Landau Fermi-liquid behaviour persists in the accessed regions of the phase diagram, where small pockets are observed. Quantum oscillation results are viewed in the context of momentum-resolved probes such as photoemission, and evidence examined from complementary experiments for potential explanations for the transformation from a large Fermi surface into small sections. Indications from quantum oscillation measurements of a low-energy Fermi surface instability at low dopings under the superconducting dome at the metal–insulator transition are reviewed, and potential implications for enhanced superconducting temperatures are discussed.

Manipulation of Germanium Nanocrystals in a Tri-Layer Insulator Structure of a Metal-Insulator-Semiconductor Memory Device

2002 ◽  
Vol 728 ◽  
Author(s):  
L.W. Teo ◽  
C.L. Heng ◽  
V. Ho ◽  
M. Tay ◽  
W.K. Choi ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Oxide Layer ◽  
Layer Structure ◽  
Charge Trapping ◽  
Middle Layer ◽  
Memory Device ◽  
Metal Insulator ◽  
Metal Insulator Semiconductor ◽  
20 Nm ◽  
Ge Nanocrystals

AbstractA metal-insulator-semiconductor (MIS) device that consists of germanium (Ge) nanocrystals embedded in a novel tri-layer insulator structure is proposed for memory applications [1]. The tri-layer structure comprises a thin (≈5nm) rapid thermal oxidation (RTO) silicon dioxide (SiO2) layer, a Ge+SiO2 middle layer (6 - 20 nm) deposited by RF co-sputtering technique and a RF-sputtered silicon dioxide capping layer. High-resolution transmission electron microscopy (HRTEM) results show that Ge nanocrystals of sizes ranging from 6 –20 nm were found after rapid thermal annealing of the trilayer structure at 1000°C for 300s. The electrical properties of these devices have been characterized using capacitance versus voltage (C-V) measurements. A significant hysteresis was observed in the C-V curves of these devices, indicating charge trapping in the composite insulator. Comparison with devices having similar tri-layer insulator structure, but with a pure sputtered oxide middle layer (i.e. minus the Ge nanocrystals), clearly indicated that the observed charge trapping is due to the presence of the Ge nanocrystals in the middle layer. The C-V measurements of devices without the capping SiO2 layer exhibited no significant hysteresis as compared to the embedded Ge nanocrystal tri-layer devices. The HRTEM micrographs showed that the presence of the capping oxide is critical in the formation of nanocrystals for this structure. By varying the thickness of the middle layer, it was found that the maximum nanocrystal size correlates well with the middle layer thickness. This indicates that the nanocrystals are well confined by the RTO oxide layer and the capping oxide layer. In addition, Ge nanocrystals formed using a thinner middle layer were found to be relatively uniform in size and distribution. This structure, therefore, offers a possibility of fabricating memory devices with controllable Ge nanocrystals size.

Charge accumulation layer induced by potassium adsorption on hydrogen terminated Si(111)(1×1)

1998 ◽  
Vol 402-404 ◽  
pp. 547-550 ◽  
Author(s):  
R. Biagi ◽  
L. Rettighieri ◽  
U. del Pennino ◽  
V. Panella ◽  
P. Dumas
Keyword(s):  
Charge Accumulation ◽  
Accumulation Layer

Silicon Carbide Nanowire Devices for Label-Free Electrical DNA Detection

2015 ◽  
Vol 821-823 ◽  
pp. 855-858 ◽  
Author(s):  
Louis Fradetal ◽  
Edwige Bano ◽  
Laurent Montes ◽  
Giovanni Atolini ◽  
Valérie Stambouli
Keyword(s):  
Silicon Carbide ◽  
Silicon Dioxide ◽  
Sol Gel ◽  
Label Free ◽  
Dna Molecules ◽  
Metal Insulator ◽  
Capacitance Measurements ◽  
Silicon Dioxide Matrix ◽  
Nanopillar Arrays

Silicon Carbide is a promising material to overtake the limitations of Si sensors used forin vivodetection. Here, two different nanodevices are presented. The first one is a SiC NWFET used for electrical detection of DNA molecules. The addition of DNA probe molecules increases the current by 25% and the hybridization with DNA targets increases by 80%. This confirms the efficiency of our sensor to detect DNA. The second one is a Metal Insulator Semicondutor capacitor composed of DNA functionalized SiC nanopillar arrays embedded in a sol-gel silicon dioxide matrix. Capacitance measurements show a singular response between 80 and 100 Hz which is attributed to the presence of DNA molecules.

Role of the Oxide Layer on the Performances of a-Si:H Schottky Structures Applied to PDS Fabrication

2006 ◽  
Vol 910 ◽  
Author(s):  
Hugo Aguas ◽  
Luis Pereira ◽  
Daniel Costa ◽  
Leandro Raniero ◽  
Elvira Fortunato ◽  
...  
Keyword(s):  
Oxide Layer ◽  
Structural Changes ◽  
Diffusion Profile ◽  
Metal Insulator ◽  
Linearity Error ◽  
Position Sensitive ◽  
Position Sensitive Detectors ◽  
532 Nm ◽  
Mis Structures

AbstractIn this work we present results of studies performed on Schottky and MIS (metal-insulator – semiconductor) PSD (position sensitive detectors) structures: substrate (glass)/ Cr (300 nm) / a-Si:H [n] (37 nm) / a-Si:H [i] (600 nm) / SiO2 (1.5 nm – for the MIS) / Au (7 nm). The effect of the interfacial oxide layer between Au and a-Si:H, for the MIS structures, was studied and compared with the Schottky, in order to determine how beneficial it could be for device performances and time degradation. For doing so, the Au thickness of 70Å was deposited by thermal evaporation on an oxide free (Schottky) and oxidized (20Å) (MIS) a-Si:H surfaces. These structures were characterized by SIMS, RBS, SEM and AFM in order to correlate the obtained diffusion profile of Au at the interface and the topography with the presence of the oxide at the interface. The results show that the Au inter-diffuses very easily in the oxide free a-Si:H surface, even at room temperature, degrading the devices performance. On the other hand, the MIS structures, with their interfacial oxide present no structural changes after annealing and the PSD produced are stable. We believe that this effect is associated with the barrier effect of the interfacial oxide that prevents the Au diffusion. The optimized 1D MIS sensors are stable and exhibit a linearity error as low as 0.8 % and sensitivities of 33 mV/cm for a 5 mW spot beam intensity at a wavelength of 532 nm, while the Schottky sensors showed a time degradation of their characteristics.

Electrical Properties of the La2O3/4H-SiC Interface Prepared by Atomic Layer Deposition Using La(iPrCp)3 and H2O

2006 ◽  
Vol 527-529 ◽  
pp. 1083-1086 ◽  
Author(s):  
Jeong Hyun Moon ◽  
Da Il Eom ◽  
Sang Yong No ◽  
Ho Keun Song ◽  
Jeong Hyuk Yim ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Atomic Layer Deposition ◽  
Leakage Current ◽  
Interfacial Layer ◽  
Atomic Layer ◽  
Mis Structure ◽  
Al2o3 Layer ◽  
Metal Insulator ◽  
Layer Deposition ◽  
Mis Structures

The La2O3 and Al2O3/La2O3 layers were grown on 4H-SiC by atomic layer deposition (ALD) method. The electrical properties of La2O3 on 4H-SiC were examined using metal-insulator-semiconductor (MIS) structures of Pt/La2O3(18nm)/4H-SiC and Pt/Al2O3(10nm)/La2O3(5nm)/4H-SiC. For the Pt/La2O3(18nm)/4H-SiC structure, even though the leakage current density was slightly reduced after the rapid thermal annealing at 500 oC, accumulation capacitance was gradually increased with increasing bias voltage due to a high leakage current. On the other hand, since the leakage current in the accumulation regime was decreased for the Pt/Al2O3/La2O3/4H-SiC MIS structure owing to the capped Al2O3 layer, the capacitance was saturated. But the saturation capacitance was strongly dependent on frequency, indicating a leaky interfacial layer formed between the La2O3 and SiC during the fabrication process of Pt/Al2O3(10nm)/ La2O3(5nm)/ 4H-SiC structure.

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