Silicon Nitride as Top Gate Dielectric for Epitaxial Graphene

2013 ◽  
Vol 740-742 ◽  
pp. 149-152 ◽  
Author(s):  
Peter Wehrfritz ◽  
Felix Fromm ◽  
Stefan Malzer ◽  
Thomas Seyller
Keyword(s):  
Silicon Nitride ◽  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Epitaxial Graphene ◽  
Plasma Process ◽  
Voltage Range ◽  
Before And After ◽  
Field Effect Devices ◽  
A Minor

Silicon nitride (SiN) was deposited by plasma enhanced chemical vapor deposition (PECVD) as a top gate dielectric on epitaxial graphene on 6H-SiC(0001). We compare x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transport measurements which were performed before and after the SiN deposition. We demonstrate that closed layers of SiN are formed without the need for surface activation and that the plasma process leads only to a minor degradation of the graphene. The SiN layer induces strong n-type doping. For a limited gate voltage range, a small hysteresis of 0.2 V is observed in top-gated field effect devices.

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Nitrogen (N2) Implantation to Suppress Growth of Interfacial Oxide in Mocvd Bst and Sputtered Bst Films

1999 ◽  
Vol 567 ◽  
Author(s):  
Renee Nieh ◽  
Wen-Jie Qi ◽  
Yongjoo Jeon ◽  
Byoung Hun Lee ◽  
Aaron Lucas ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Interfacial Layer ◽  
Gate Dielectric ◽  
Nitrogen Concentration ◽  
Chemical Vapor ◽  
Future Generation ◽  
Oxide Thickness ◽  
Layer Growth ◽  
X Ray ◽  
Bst Films

ABSTRACTBa0.5Sr0.5TiO3 (BST) is one of the high-k candidates for replacing SiO2 as the gate dielectric in future generation devices. The biggest obstacle to scaling the equivalent oxide thickness (EOT) of BST is an interfacial layer, SixOy, which forms between BST and Si. Nitrogen (N2) implantation into the Si substrate has been proposed to reduce the growth of this interfacial layer. In this study, capacitors (Pt/BST/Si) were fabricated by depositing thin BST films (50Å) onto N2 implanted Si in order to evaluate the effects of implant dose and annealing conditions on EOT. It was found that N2 implantation reduced the EOT of RF magnetron sputtered and Metal Oxide Chemical Vapor Deposition (MOCVD) BST films by ∼20% and ∼33%, respectively. For sputtered BST, an implant dose of 1×1014cm−;2 provided sufficient nitrogen concentration without residual implant damage after annealing. X-ray photoelectron spectroscopy data confirmed that the reduction in EOT is due to a reduction in the interfacial layer growth. X-ray diffraction spectra revealed typical polycrystalline structure with (111) and (200) preferential orientations for both films. Leakage for these 50Å BST films is on the order of 10−8 to 10−5 A/cm2—lower than oxynitrides with comparable EOTs.

Atomic Hydrogen Effects on the Optical and Electrical Properties of Transparent Conducting Oxides For a-Si:H TFT-LCDs

1996 ◽  
Vol 424 ◽  
Author(s):  
Je-Hsiung Lan ◽  
Jerzy Kanicki
Keyword(s):  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Atomic Hydrogen ◽  
Chemical Vapor ◽  
Optical Transmittance ◽  
Ex Situ ◽  
Hydrogen Treatment ◽  
X Ray ◽  
Conducting Oxides ◽  
Before And After

AbstractThe effects of the atomic hydrogen treatment (H-treatment) of indium-tin oxide (ITO) and aluminum-doped zinc oxide (AZO) films have been investigated. The atomic hydrogen was generated by hot-wire chemical vapor deposition (HW-CVD) technique. Experimental results have shown that AZO films are chemically very stable under the H-treatment; almost no variation in the optical transmittance and electrical resistivity was observed. On the contrary, ITO films, either prepared by sputtering with ex-situ or in-situ thermal-annealing, have shown severe optical and electrical degradation and surface whitening after the H-treatment. SEM studies of the H-treated ITO surfaces have revealed that the surface whitening was due to the increase in surface roughness and the formation of granule-like metallic balls. Auger electron spectroscopy has indicated that the balls were mainly composed of indium atoms and the areas between balls were rich in oxygen atoms. These results were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy measurements done on ITO before and after the H-treatment. Finally, we have demonstrated that a-SiO, deposited by PECVD will completely suppress the chemical reaction between ITO surfaces and atomic hydrogen generated by HW-CVD technique.

An analysis of preferred orientation in YBa2Cu3O7–x superconducting films deposited by CVD on single-crystal and polycrystalline substrates

1994 ◽  
Vol 9 (4) ◽  
pp. 250-259 ◽  
Author(s):  
E. A. Judson ◽  
D. N. Hill ◽  
R. A. Young ◽  
J. R. Cagle ◽  
W. J. Lackey ◽  
...  
Keyword(s):  
Single Crystal ◽  
Chemical Vapor ◽  
Preferred Orientation ◽  
Superconducting Properties ◽  
High Temperature Anneal ◽  
Pole Figures ◽  
Before And After ◽  
Diffraction Patterns ◽  
A Minor ◽  
Orientation Phenomenon

YBa2Cu3O7–x films were deposited by chemical vapor deposition (CVD) onto single-crystal MgO, single-crystal Al2O3, and polycrystalline Al2O3 substrates, characterized before and after annealing, and tested for their superconducting properties. The preferred orientation in the films was analyzed (i) with pole figures and (ii) by comparison of experimental x-ray powder diffraction patterns with those calculated for the material using the March–Dollase function to model the degree of preferred orientation. Preferred orientation was significant in as-deposited films, with March coefficients ranging from 0.1–0.5 (random orientation would have a coefficient of 1.0). The (006) pole figures of the films on single crystal substrates exhibited uniquely symmetric patterns. On single-crystal MgO before annealing, a minor secondary orientation of (006) poles in the film was observed in a pattern consistent with the symmetry of major crystallographic directions of MgO. On single-crystal Al2O3 after annealing, a “dual orientation” phenomenon was observed. The high-temperature anneal destroyed the orientation and superconducting properties of the CVD films deposited at high temperatures.

Low-Temperature Chemical-Vapor-Deposition of Silicon-Nitride from Tetra-Silane and Hydrogen Azide

1992 ◽  
Vol 284 ◽  
Author(s):  
Ryoichi Ishihara ◽  
Hiroshi Kanoh ◽  
Yasutaka Uchida ◽  
Osamu Sugiura ◽  
Masakiyo Matsumura
Keyword(s):  
Chemical Vapor Deposition ◽  
Silicon Nitride ◽  
Vapor Deposition ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Atomic Ratio ◽  
Breakdown Field ◽  
Silicon Thin Film ◽  
Silicon Nitride Films ◽  
Low Field

ABSTRACTSilicon nitride films have been successfully deposited at a temperature as low as 300°C by chemical-vapor-deposition using tctra-silane (Si4 H10) and hydrogen azidc (HN3). Atomic ratio (N/Si) of the film deposited at 400°C was 1.47, i.e., the film was N-rich. Total hydrogen content was about 25atomic%. The breakdown-field strength was 6.5MV/cm at leakage-current density of 1μA/cm2, and the low-field resistivity was more than 1015 Ωcm. Similar electrical characteristics were obtained from films deposited at a temperature range between 300°C and 500°C. Amorphous silicon thin-film transistors equipped with this film as the gate dielectric showed good transfer characteristics.

Chemical Vapor Deposition of ZrxTi1-xO and HfxTi1-xO Thin Films Using the Composite Anhydrous Nitrate Precursors

2006 ◽  
Vol 917 ◽  
Author(s):  
Qi-Yue Shao ◽  
Ai-Dong Li ◽  
Wen-Qi Zhang ◽  
Di Wu ◽  
Zhi-Guo Liu ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Photoelectron Spectroscopy ◽  
Gate Dielectric ◽  
Chemical Vapor ◽  
Complementary Metal Oxide Semiconductor ◽  
Heating Time ◽  
Oxide Semiconductor ◽  
Molar Ratio ◽  
X Ray ◽  
The Individual

AbstractZr/Ti an Hf/Ti composite nitrate were developed as single-source precursors for deposition of multi-component metal oxide films. X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) analyses confirmed that ZrxTi1-xO2 and HfxTi1-xO2 films were successfully prepared by the CVD technique from these composite precursors. The Zr/Ti nitrate can be taken as a solid solution of the individual Zr and Ti nitrate, and the Zr/Ti molar ratio in as-deposited ZrxTi1-xO2 films is nicely consistent with that of the precursor. The Hf/Ti nitrate appears to be a mixture of the Zr and Ti nitrates and the composition of the as-deposited HfxTi1-xO2 films depends remarkably on the heating time of precursor. Both ZrxTi1-xO2 and HfxTi1-xO2 films exhibit trading-off properties between band gap and dielectric constant, which suggesting that ZrxTi1-xO2 and HfxTi1-xO2 can be the promising candidates for gate dielectric application to improve the scalability and reduce the leakage current of the next generation complementary metal-oxide-semiconductor transistor (CMOS) devices.

Polymeric phthalocyanine sheets as electrocatalytic electrodes for water-oxidation

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1166-1172 ◽  
Author(s):  
Clemens Geis ◽  
Simon P. Schneider ◽  
Derck Schlettwein
Keyword(s):  
Cyclic Voltammetry ◽  
Photoelectron Spectroscopy ◽  
Water Oxidation ◽  
Chemical Vapor ◽  
Electrical Energy ◽  
Optical Absorption Spectroscopy ◽  
Voltage Range ◽  
Positive Voltage ◽  
Current Densities ◽  
Stable Current

Polymeric copper and cobalt phthalocyanine (Cu-pPc and Co-pPc) were prepared as thin films on fluorine-doped tin oxide (FTO) glass from evaporated metal films via a chemical vapor deposition (CVD) process with 1,2,4,5-tetracyanobenzene (TCB). The films were characterized by optical absorption spectroscopy in transmission and by X-ray photoelectron spectroscopy. Different oxidation states of the metal atoms were detected indicating different chemical environments. Reversible electrochemical reduction of Cu-pPc and Co-pPc was observed and monitored by cyclic voltammetry and spectroelectrochemical investigations. Cyclic voltammetry and chronoamperometry in the positive voltage range led to anodic currents in the oxygen evolution reaction that could be performed at stable current densities and showed a remarkable efficiency in particular for electrodes of Co-pPc in this reaction, attractive for the conversion of electrical energy into chemical energy.

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