scholarly journals Influence of N2/O2 Partial Pressure Ratio during Channel Layer Deposition on the Temperature and Light Stability of a-InGaZnO TFTs

2019 ◽  
Vol 9 (9) ◽  
pp. 1880 ◽  
Author(s):  
Xiaoming Huang ◽  
Dong Zhou ◽  
Weizong Xu
Keyword(s):  
Partial Pressure ◽  
Photoelectron Spectroscopy ◽  
Pressure Ratio ◽  
Interfacial Region ◽  
Electrical Stability ◽  
Vacancy Defects ◽  
Bias Stress ◽  
Layer Deposition ◽  
O2 Partial Pressure ◽  
Interface Barrier

The electrical characteristics of amorphous InGaZnO (a-IGZO) thin film transistors (TFTs) deposited with different N2/O2 partial pressure ratios (PN/O) are investigated. It is found that the device with 20% PN/O exhibits enhanced electrical stability after positive-bias-stress temperature (PBST) and negative-bias-stress illumination (NBSI), presenting decreased threshold voltage drift (ΔVth). Compared to the N-free TFT, the average effective interface barrier energy (Eτ) of the TFT with 20% PN/O is increased from 0.37 eV to 0.57 eV during the bias-stress process, which agrees with the suppressed ΔVth from 3.0 V to 1.12 V after the PBS at T = 70 °C. X-ray photoelectron spectroscopy analysis revealed that the enhanced stability of the a-IGZO TFT with 20% PN/O should be ascribed to the control of oxygen vacancy defects at the interfacial region.

scholarly journals Nucleation Studies of HfO2 Thin Films Produced by Atomic Layer Deposition

2007 ◽  
Vol 996 ◽  
Author(s):  
Justin C. Hackley ◽  
J. Derek Demaree ◽  
Theodosia Gougousi
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Flow Reactor ◽  
Atomic Layer ◽  
Sample Surface ◽  
Interfacial Region ◽  
Initial Growth ◽  
Layer Deposition ◽  
Similar Growth

AbstractA hot wall Atomic Layer Deposition (ALD) flow reactor equipped with a Quartz Crystal Microbalance (QCM) has been used for the deposition of HfO2 thin films with tetrakis (dimethylamino) hafnium (TDMAH) and H2O as precursors. HfO2 films were deposited on H-terminated Si and SC1 chemical oxide starting surfaces. Spectroscopic ellipsometry (SE) and QCM measurements confirm linear growth of the films at a substrate temperature of 275°C. FTIR spectra indicate the films are amorphous as-deposited. Two distinct growth regimes are observed: from 1-50 cycles, both surfaces display similar growth rates of about 1.0Å/cycle; from 50-200 cycles, HfO2 growth is decreased by about 15% to ~0.87Å/cycle on both surfaces. Nucleation and initial growth behavior of the films on Si-H were examined using X-ray photoelectron spectroscopy (XPS). Angle-resolved XPS, at take-off angles of θ=0, 15, 30, 45 and 60° measured from the normal to the sample surface, is used to probe the interfacial region of thin films (4, 7, 10, 15 and 25 cycles) on H-terminated samples. Initially, an interfacial layer comprised of a SiOx/HfSiOx mixture is grown between 1-10 ALD cycles. We observe that the Si/HfO2 interface is unstable, and oxidation continues up to the 25th ALD cycle, reaching a thickness of ~18Å.

The Effects of Oxygen Partial Pressure on Interface States and Ferroelectric Properties of PZT/PbO/Si (MFIS) Structures

2007 ◽  
Vol 544-545 ◽  
pp. 1077-1080
Author(s):  
Chul Ho Park ◽  
Mi Sook Won ◽  
Young Gook Son
Keyword(s):  
Thin Film ◽  
Partial Pressure ◽  
Photoelectron Spectroscopy ◽  
Ferroelectric Properties ◽  
Pressure Ratio ◽  
Buffer Layers ◽  
Interface Condition ◽  
Si Substrate ◽  
Pzt Thin Film ◽  
P Type

Pt/PZT/PbO/Si with the MFIS structure was deposited on the p-type (100) Si substrate by the r.f. magnetron sputtering method with Pb1.1Zr0.53Ti0.47O3 and PbO targets. From the X-ray photoelectron spectroscopy (XPS) results, we could confirm that the partial pressure ratio during PbO deposition affects the interface condition of PbO/Si and the chemical state of Pb existing at the surface of the PZT thin film. The maximum value of the memory window is 3.0 V under the applied voltage of 9V for Pt/PZT (200 nm 400°C)/PbO (80 nm, 300°C)/Si structures with the PbO buffer layer deposited at the partial pressure of 7:3. From these results, we could assume that the PbO buffer layers play a role of the diffusion barrier between the PZT thin film and the Si substrate as well as the seed layer.

Separation of carotid body chemoreceptor responses to O2 and CO2 by oligomycin and by antimycin A

1982 ◽  
Vol 242 (3) ◽  
pp. C200-C206 ◽  
Author(s):  
E. Mulligan ◽  
S. Lahiri
Keyword(s):  
Steady State ◽  
Carbonic Anhydrase ◽  
Partial Pressure ◽  
Carotid Body ◽  
Body Tissue ◽  
Antimycin A ◽  
Tissue Ph ◽  
Co2 Partial Pressure ◽  
O2 Partial Pressure ◽  
Metabolic Hypothesis

The cat carotid chemoreceptor O2 and CO2 responses can be separated by oligomycin and by antimycin A. Both of these agents greatly diminish or abolish the chemoreceptor O2 response but not the nicotine or CO2 responses. After either oligomycin or antimycin, the responses to increases and decreases in arterial CO2 partial pressure (PaCO2) consisted of increases and decreases in activity characterized respectively by exaggerated overshoots and undershoots. These were eliminated by the carbonic anhydrase inhibitor, acetazolamide, suggesting that they resulted from changes in carotid body tissue pH. The steady-state PaCO2 response remaining after oligomycin was no longer dependent on arterial O2 partial pressure (PaO2). All effects of antimycin were readily reversible in about 20 min. The separation of the responses to O2 and CO2 indicates that there may be at least partially separate pathways of chemoreception for these two stimuli. The similarity of the oligomycin and antimycin results supports the metabolic hypothesis of chemoreception.

Interaction of hypoxia and hypercapnia on cerebral hemodynamics and brain electrical activity in dogs

1987 ◽  
Vol 253 (4) ◽  
pp. H890-H897 ◽  
Author(s):  
R. W. McPherson ◽  
D. Eimerl ◽  
R. J. Traystman
Keyword(s):  
Partial Pressure ◽  
Elevated Level ◽  
Severe Hypoxia ◽  
O2 Uptake ◽  
Animal Group ◽  
Moderate Hypoxia ◽  
Co2 Partial Pressure ◽  
Arterial Blood ◽  
O2 Partial Pressure ◽  
O2 Delivery

The interaction of hypoxic hypoxia, hypercapnia, and mean arterial blood pressure (MABP) was studied in 15 pentobarbital-anesthetized ventilated dogs. In one group of animals (n = 5) hypercapnia [arterial CO2 partial pressure (PaCO2) approximately 50 Torr] was added to both moderate hypoxia and severe hypoxia. Moderate hypoxia [arterial O2 partial pressure (PaO2) = 36 mmHg] increased MABP and cerebral blood flow (CBF) without changes in cerebral O2 uptake (CMRO2). Superimposed hypercapnia increased CBF and MABP further with no change in CMRO2. In another group of animals (n = 5), a MABP increase of approximately 40 mmHg during moderate hypoxia without hypercapnia did not further increase CBF, suggesting intact autoregulation. Thus, during moderate hypoxia, hypercapnia is capable of increasing CBF. Severe hypoxia (PaO2 = 22 mmHg) increased CBF, but MABP and CMRO2 declined. Superimposed hypercapnia further decreased MABP and decreased CBF from its elevated level and further decreased CMRO2. Raising MABP under these circumstances in another animal group (n = 5) increased CBF above the level present during severe hypoxia alone and increased CMRO2. The change in CBF and CMRO2 during severe hypoxia plus hypercapnia with MABP elevation were not different from that severe hypoxia alone. We conclude that, during hypoxia sufficiently severe to impair CMRO2, superimposed hypercapnia has a detrimental influence due to decreased MABP, which causes a decrease in CBF and cerebral O2 delivery.

scholarly journals Structural and Optical Properties of Luminescent Copper(I) Chloride Thin Films Deposited by Sequentially Pulsed Chemical Vapour Deposition

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Richard Krumpolec ◽  
Tomáš Homola ◽  
David Cameron ◽  
Josef Humlíček ◽  
Ondřej Caha ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Chemical Vapour Deposition ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Atomic Layer ◽  
Nanocrystalline Films ◽  
Zinc Blende ◽  
Layer Deposition

Sequentially pulsed chemical vapour deposition was used to successfully deposit thin nanocrystalline films of copper(I) chloride using an atomic layer deposition system in order to investigate their application to UV optoelectronics. The films were deposited at 125 °C using [Bis(trimethylsilyl)acetylene](hexafluoroacetylacetonato)copper(I) as a Cu precursor and pyridine hydrochloride as a new Cl precursor. The films were analysed by XRD, X-ray photoelectron spectroscopy (XPS), SEM, photoluminescence, and spectroscopic reflectance. Capping layers of aluminium oxide were deposited in situ by ALD (atomic layer deposition) to avoid environmental degradation. The film adopted a polycrystalline zinc blende-structure. The main contaminants were found to be organic materials from the precursor. Photoluminescence showed the characteristic free and bound exciton emissions from CuCl and the characteristic exciton absorption peaks could also be detected by reflectance measurements.

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