scholarly journals A Stable and Efficient Pt/n-Type Ge Schottky Contact That Uses Low-Cost Carbon Paste Interlayers

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 259
Author(s):  
Pei-Te Lin ◽  
Jia-Wei Chang ◽  
Syuan-Ruei Chang ◽  
Zhong-Kai Li ◽  
Wei-Zhi Chen ◽  
...  

Ge-based Schottky diodes find applications in high-speed devices. However, Fermi-level pinning is a major issue for the development of Ge-based diodes. This study fabricates a Pt/carbon paste (CP)/Ge Schottky diode using low-cost CP as an interlayer. The Schottky barrier height (ΦB) is 0.65 eV for Pt/CP/n-Ge, which is a higher value than the value of 0.57 eV for conventional Pt/n-Ge. This demonstrates that the CP interlayer has a significant effect. The relevant junction mechanisms are illustrated using feasible energy level band diagrams. This strategy results in greater stability and enables a device to operate for more than 500 h under ambient conditions. This method realizes a highly stable Schottky contact for n-type Ge, which is an essential element of Ge-based high-speed electronics.

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.


2019 ◽  
Vol 68 ◽  
pp. 212-217 ◽  
Author(s):  
Chun-Ying Huang ◽  
Pei-Te Lin ◽  
Hao-Che Cheng ◽  
Fang-Chi Lo ◽  
Po-Sheng Lee ◽  
...  

1992 ◽  
Vol 262 ◽  
Author(s):  
Kai Zhang ◽  
D. L. Miller

ABSTRACTThe effect of LT GaAs on the effective barrier height of the epitaxial Al/GaAs Schottky contact was investigated for the first time by inserting a thin LT GaAs layer (50 ∼ 500Å) between the in situ deposited Al film and conventional MBE GaAs epitaxial layer. The activation energy plot of saturation current for the devices showed that the effective barrier height exhibits a dependence on LT GaAs thickness and reaches a saturated barrier height when the LT GaAs layer exceeds a critical thickness. Compared to the samples which had no LT GaAs layer, the effective Schottky barrier height was decreased from 0.79 eV to 0.35 eV for the n-GaAs samples, and increased from 0.55 eV to 0.72 eV for the p-GaAs samples. The Schottky barrier height modification achieved by LT GaAs is tentatively explained in the terms of a bulk Fermi level pinning model. The work described here suggests that LT GaAs can be used as a defect source with controlled thickness to study defect associated phenomena such as Schottky barrier height modification.


2010 ◽  
Vol 645-648 ◽  
pp. 669-672 ◽  
Author(s):  
Masashi Kato ◽  
H. Ono ◽  
Masaya Ichimura

We performed electrochemical deposition of ZnO on the surfaces of 4H-SiC epilayers and characterized Ni Schottky diodes fabricated on the same epilayers. We found correlation between positions where ZnO was deposited and positions where Schottky barrier height of Ni contacts is lower than of the rest of the contacts. Parts of the surface where ZnO was deposited were observed by AFM after removal of the ZnO layer, and we discussed the origin of the low Schottky barrier height from the AFM images.


1984 ◽  
Vol 37 ◽  
Author(s):  
Jerry M. Woodall

AbstractExcept for a few special cases, the electrical and optical properties of most III-V semiconductor surfaces and interfaces can be explained in terms of surface Fermi level pinning. However, despite years of research there is no universal agreement on the origin of this pinning. This problem is of more than just academic interest since pinning affects optoelectronic device performance via surface recombination losses, and high speed device performance through uncontrollable ohmic and Schottky contact properties for MESFETs and through a high interface trap density for MISFETs.This talk reviews some of the approaches to the pinning problem and presents some recent results on the role of misfit dislocations in pinning. In particular it will be shown that there are are several models which can explain the usually observed pinning positions. However, we have developed a modified work function model capable of explaining both the usual pinning positions and the experimentally observed exceptions in Schottky barrier height for some metal/semiconductor interfaces. The electrical properties of lattice mismatched GaInAs/GaAs heterojunctions suggest that Fermi level pinning occurs at misfit dislocations.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.


2007 ◽  
Author(s):  
R. E. Crosbie ◽  
J. J. Zenor ◽  
R. Bednar ◽  
D. Word ◽  
N. G. Hingorani

2016 ◽  
Vol 30 (06) ◽  
pp. 1650063 ◽  
Author(s):  
Jingwen Sun ◽  
Jian Sun ◽  
Yunji Yi ◽  
Lucheng Qv ◽  
Shiqi Sun ◽  
...  

A low-cost and high-speed electro-optic (EO) switch using the guest–host EO material Disperse Red 1/Polymethyl Methacrylate (DR1/PMMA) was designed and fabricated. The DR1/PMMA material presented a low processing cost, an excellent photostability and a large EO coefficient of 13.1 pm/V. To improve the performance of the switch, the in-plane buried electrode structure was introduced in the polymer Mach–Zehnder waveguide to improve the poling and modulating efficiency. The characteristic parameters of the waveguide and the electrodes were carefully designed and the fabrication process was strictly controlled. Under 1550 nm, the insertion loss of the device was 12.7 dB. The measured switching rise time and fall time of the switch were 50.00 ns and 54.29 ns, respectively.


2021 ◽  
Vol 11 (10) ◽  
pp. 4610
Author(s):  
Simone Berneschi ◽  
Giancarlo C. Righini ◽  
Stefano Pelli

Glasses, in their different forms and compositions, have special properties that are not found in other materials. The combination of transparency and hardness at room temperature, combined with a suitable mechanical strength and excellent chemical durability, makes this material indispensable for many applications in different technological fields (as, for instance, the optical fibres which constitute the physical carrier for high-speed communication networks as well as the transducer for a wide range of high-performance sensors). For its part, ion-exchange from molten salts is a well-established, low-cost technology capable of modifying the chemical-physical properties of glass. The synergy between ion-exchange and glass has always been a happy marriage, from its ancient historical background for the realisation of wonderful artefacts, to the discovery of novel and fascinating solutions for modern technology (e.g., integrated optics). Getting inspiration from some hot topics related to the application context of this technique, the goal of this critical review is to show how ion-exchange in glass, far from being an obsolete process, can still have an important impact in everyday life, both at a merely commercial level as well as at that of frontier research.


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