GaN ON SILICON SUBSTRATE WITH AlN BUFFER LAYER FOR UV PHOTODIODE

2012 ◽  
Vol 21 (01) ◽  
pp. 1250014 ◽  
Author(s):  
L. S. CHUAH ◽  
S. M. THAHAB ◽  
Z. HASSAN
Keyword(s):  
Schottky Barrier ◽  
Buffer Layer ◽  
Barrier Height ◽  
Silicon Substrate ◽  
Dark Current ◽  
Schottky Barrier Height ◽  
Buffer Layers ◽  
Current Ratio ◽  
Principal Mechanism ◽  
Aln Buffer

Nitrogen plasma-assisted molecular beam epitaxy (PAMBE) deposited GaN thin films on (111) n-type silicon substrate with different thickness AlN buffer layers are investigated and distinguished by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman scattering. The thickness of AlN buffer layer ranged from 200 nm to 300 nm. Besides that, the electrical characteristics of the GaN thin film for ultraviolet detecting utilizations are studied by calculating the photo current/dark current ratio on a metal-semiconductor-metal (MSM) photodiode with and without the illumination of Hg-lamp source. The devices have been tested over room temperature (RT). The photocurrent analysis, together with the study of Schottky barrier height (SBH) development, ascertain that the principal mechanism of photo transport is thermionic emission. The photocurrent value is rigorously dependent on Schottky barrier height. The GaN/AlN(200 nm)/n-Si MSM photodiode produces the highest photo/dark current ratio for the lowest strain that consists of the GaN film grown on the AlN (200 nm) buffer layer.

Defect Reduction in Si-based Metal-Semiconductor-Metal Photodetectors with Cryogenic Processed Schottky Contacts

2005 ◽  
Vol 864 ◽  
Author(s):  
M. Li ◽  
W. A. Anderson
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Dark Current ◽  
Schottky Barrier Height ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Metal Deposition ◽  
Active Area ◽  
Electrode Spacing ◽  
Metal Semiconductor Metal

AbstractMetal-Semiconductor-Metal photodetectors (MSM-PD's) and simple Schottky diodes were fabricated using a low temperature (LT) technique to greatly reduce the device dark current. LT processing for metal deposition increased Schottky barrier height by improving the interface between metal and semiconductor to reduce the leakage current of the device. The structure consists of a 20 Å oxide over the active area to passivate surface states, a thicker oxide under contact pads to reduce dark current and the interdigitated Schottky contacts. A comparison was made for Schottky metal deposited with the substrate at 25 °C or -50 °C (LT). The devices fabricated using the LT process had better I-V characteristics compared to detectors fabricated using the standard room temperature (RT) metal deposition technique. The dark current for the LT film was found to be one to three orders lower in magnitude compared to the film deposited at RT. In one case, for example, the dark current was significantly reduced from 1.69 nA to 4.58 pA at 1.0 V. The active area for the device was determined to be 36 × 50 μm2 with 4 μm electrode width and 4 μm electrode spacing. Additionally, LT-MSM-PD's exhibited an excellent linear relationship between the photo-current and the incident light power. The Schottky barrier height for LT processing was found to be 0.79 eV; however, this value was 0.1 eV more than that of the same contact obtained by RT processing.

scholarly journals A Study about Schottky Barrier Height and Ideality Factor in Thin Film Transistors with Metal/Zinc Oxide Nanoparticles Structures Aiming Flexible Electronics Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1188
Author(s):  
Ivan Rodrigo Kaufmann ◽  
Onur Zerey ◽  
Thorsten Meyers ◽  
Julia Reker ◽  
Fábio Vidor ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Flexible Electronics ◽  
Thin Film Transistors ◽  
Zinc Oxide Nanoparticles ◽  
Schottky Barrier Height ◽  
Oxide Nanoparticles ◽  
Semiconductor Interfaces

Zinc oxide nanoparticles (ZnO NP) used for the channel region in inverted coplanar setup in Thin Film Transistors (TFT) were the focus of this study. The regions between the source electrode and the ZnO NP and the drain electrode were under investigation as they produce a Schottky barrier in metal-semiconductor interfaces. A more general Thermionic emission theory must be evaluated: one that considers both metal/semiconductor interfaces (MSM structures). Aluminum, gold, and nickel were used as metallization layers for source and drain electrodes. An organic-inorganic nanocomposite was used as a gate dielectric. The TFTs transfer and output characteristics curves were extracted, and a numerical computational program was used for fitting the data; hence information about Schottky Barrier Height (SBH) and ideality factors for each TFT could be estimated. The nickel metallization appears with the lowest SBH among the metals investigated. For this metal and for higher drain-to-source voltages, the SBH tended to converge to some value around 0.3 eV. The developed fitting method showed good fitting accuracy even when the metallization produced different SBH in each metal-semiconductor interface, as was the case for gold metallization. The Schottky effect is also present and was studied when the drain-to-source voltages and/or the gate voltage were increased.

Schottky barrier height on thermally oxidized InAlN surface evaluated by electrical and optical measurements

2011 ◽  
Vol 98 (16) ◽  
pp. 162111 ◽  
Author(s):  
J. Kováč ◽  
R. Šramatý ◽  
A. Chvála ◽  
H. Sibboni ◽  
E. Morvan ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Optical Measurements

Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Thin Films ◽  
Zno Films ◽  
Si Substrates ◽  
Atomic Force ◽  
Structure Morphology ◽  
Aln Buffer

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

Effective Schottky Barrier Height Lowering by TiN Capping Layer for TiSix/Si Power Diode

2015 ◽  
Vol 36 (6) ◽  
pp. 597-599 ◽  
Author(s):  
Lin-Lin Wang ◽  
Wu Peng ◽  
Yu-Long Jiang ◽  
Bing-Zong Li
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Capping Layer ◽  
Power Diode

Schottky Barrier Height Engineering in NiGe/n-Ge(001) Contacts by Germanidation Induced Dopant Segregation

2007 ◽  
Vol 994 ◽  
Author(s):  
S. L. Liew ◽  
C. T. Chua ◽  
D. H. L Seng ◽  
D. Z. Chi
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Barrier Height ◽  
Dopant Segregation

AbstractSchottky barrier height (ÖB) engineering of NiGe/n-Ge(001) diodes was achieved through germanidation induced dopant segregation on As implanted-Ge substrates. was reduced from 0.55 eV to 0.16 eV with increasing As dose on n-Ge(001) while on p-Ge(001), the diodes exhibited increasing ÖB.

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