scholarly journals The Achievement of a Zinc Oxide-Based Homojunction Diode Using Radio Frequency Magnetron Cosputtering System

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hung-Jen Chiu ◽  
Tai-Hong Chen ◽  
Li-Wen Lai ◽  
Ching-Ting Lee ◽  
Jhen-Dong Hong ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Radio Frequency ◽  
Ohmic Contact ◽  
Indium Tin Oxide ◽  
Reverse Current ◽  
Specific Contact Resistance ◽  
Zno Film ◽  
Current Voltage ◽  
Specific Contact ◽  
Contact Electrode

(Al + N)-codopedp-type zinc oxide (ZnO)/undopedn-type ZnO homojunction structure was deposited onto Si (100) substrate by using radio frequency (rf) magnetron cosputtering system. Transparent indium tin oxide (ITO)-ZnO cosputtered film was employed as the ohmic contact electrode to then-type ZnO film, and the specific contact resistance was optimized to2.9×10-6 Ω cm2after treating by a rapid thermal annealing (RTA) process at 400°C for 5 min under vacuum ambient. The ohmic contact behavior between the metallic Ni/Au andp-ZnO film also was improved to3.5×10-5 Ω cm2after annealing at 300°C for 3 min under nitrogen ambient. The interfacial diffusion of these ohmic contact systems which led to the optimization of the specific contact resistances by the RTA process was investigated by the Auger electron spectroscopy (AES) depth profile measurements. The diode characteristics of the resultingp-ZnO/n-ZnO homojunction structure realized with these ohmic contact electrodes were confirmed by current-voltage (I-V) measurement, which performed a forward turn-on voltage of 1.44 V with a reverse current of1.1×10-5 A at −2 V.

scholarly journals Reliable Ohmic Contact Properties for Ni/Hydrogen-Terminated Diamond at Annealing Temperature up to 900 °C

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 470
Author(s):  
Xiaolu Yuan ◽  
Jiangwei Liu ◽  
Jinlong Liu ◽  
Junjun Wei ◽  
Bo Da ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
Annealing Temperature ◽  
Electronic Devices ◽  
Schottky Contacts ◽  
Specific Contact Resistance ◽  
Annealing Temperatures ◽  
Current Voltage ◽  
Specific Contact ◽  
Contact Electrode

Ohmic contact with high thermal stability is essential to promote hydrogen-terminated diamond (H-diamond) electronic devices for high-temperature applications. Here, the ohmic contact characteristics of Ni/H-diamond at annealing temperatures up to 900 °C are investigated. The measured current–voltage curves and deduced specific contact resistance (ρC) are used to evaluate the quality of the contact properties. Schottky contacts are formed for the as-received and 300 °C-annealed Ni/H-diamonds. When the annealing temperature is increased to 500 °C, the ohmic contact properties are formed with the ρC of 1.5 × 10−3 Ω·cm2 for the Ni/H-diamond. As the annealing temperature rises to 900 °C, the ρC is determined to be as low as 6.0 × 10−5 Ω·cm2. It is believed that the formation of Ni-related carbides at the Ni/H-diamond interface promotes the decrease in ρC. The Ni metal is extremely promising to be used as the ohmic contact electrode for the H-diamond-based electronic devices at temperature up to 900 °C.

scholarly journals Surface Modification on the Sputtering-Deposited ZnO Layer for ZnO-Based Schottky Diode

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ren-Hao Chang ◽  
Kai-Chao Yang ◽  
Tai-Hong Chen ◽  
Li-Wen Lai ◽  
Tsung-Hsin Lee ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Schottky Diode ◽  
Ohmic Contact ◽  
Indium Tin Oxide ◽  
Photoelectron Spectroscopy ◽  
Layer Surface ◽  
Barrier Heights ◽  
Ammonium Sulfide ◽  
Current Voltage ◽  
Contact Electrode

We prepare a zinc oxide- (ZnO-) based Schottky diode constructed from the transparent cosputtered indium tin oxide- (ITO-) ZnO ohmic contact electrode and Ni/Au Schottky metal. After optimizing the ohmic contact property and removing the ion-bombardment damages using dilute HCl etching solution, the dilute hydrogen peroxide (H2O2) and ammonium sulfide (NH4)2Sxsolutions, respectively, are employed to modify the undoped ZnO layer surface. Both of the Schottky barrier heights with the ZnO layer surface treated by these two solutions, evaluated from the current-voltage (I-V) and capacitance-voltage (C-V) measurements, are remarkably enhanced as compared to the untreated ZnO-based Schottky diode. Through the X-ray photoelectron spectroscopy (XPS) and room-temperature photoluminescence (RTPL) investigations, the compensation effect as evidence of the increases in the O–H and OZnacceptor defects appearing on the ZnO layer surface after treating by the dilute H2O2solution is responsible for the improvement of the ZnO-based Schottky diode. By contrast, the enhancement on the Schottky barrier height for the ZnO layer surface treated by using dilute (NH4)2Sxsolution is attributed to both the passivation and compensation effects originating from the formation of the Zn–S chemical bond andVZnacceptors.

Ohmic Contact Behavior of Pt/Ni/Au to p-ZnO

2006 ◽  
Vol 928 ◽  
Author(s):  
Ji-Myon Lee ◽  
Kyoung-Kook Kim ◽  
Hitoshi Tampo ◽  
Akimasa Yamada ◽  
Shigeru Niki
Keyword(s):  
Ohmic Contact ◽  
Profile Analysis ◽  
Specific Contact Resistance ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Current Voltage ◽  
Glancing Angle ◽  
Specific Contact ◽  
Current Voltage Characteristics ◽  
Lower Contact

ABSTRACTThe electrical properties of single Pt (30 nm) and Pt (30 nm)/Ni (30nm)/Au(50nm) multilayer contacts on moderately doped p-ZnO (Na = 5.0 × 1017 /−3) were investigated. Although linear current-voltage characteristics were observed for all samples, a sample that was annealed for 1 min at a temperature above 500 °C resulted in an ohmic contact with good characteristics. The best ohmic contact to p-type ZnO was obtained using a Pt/Ni/Au multilayer contact that was annealed at 600 °C for 1 min under a N2 ambient, showing a specific contact resistance Rc of 1.97 × 10−5 Ω cm2. The fundamental mechanisms for the lower contact resistivity of Pt/Ni/Au contacts are discussed based on glancing angle x-ray diffraction results and Auger depth profile analysis of the multilayer alloying process. Furthermore, we fabricated a ZnO p-n homojunction using Pt/Ni/Au and Ti/Au as the p-type and n-type ohmic contact metal, respectively. The threshold voltage was determined to be about 3.7 V, comparable to the bandgap energy of ZnO.

Effect of Au distribution in NiO/Au film on the ohmic contact formation to p-type GaN

2005 ◽  
Vol 20 (2) ◽  
pp. 456-463 ◽  
Author(s):  
Jiin-Long Yang ◽  
J.S. Chen ◽  
S.J. Chang
Keyword(s):  
Electron Microscopy ◽  
Ohmic Contact ◽  
Incident Angle ◽  
Specific Contact Resistance ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Specific Contact ◽  
P Type

The distribution of Au and NiO in NiO/Au ohmic contact on p-type GaN was investigated in this work. Au (5 nm) films were deposited on p-GaN substrates by magnetron sputtering. Some of the Au films were preheated in N2 ambient to agglomerate into semi-connected structure (abbreviated by agg-Au); others were not preheated and remained the continuous (abbreviated by cont-Au). A NiO film (5 nm) was deposited on both types of samples, and all samples were subsequently annealed in N2 ambient at the temperatures ranging from 100 to 500 °C. The surface morphology, phases, and cross-sectional microstructure were investigated by scanning electron microscopy, glancing incident angle x-ray diffraction, and transmission electron microscopy. I-V measurement on the contacts indicates that only the 400 °C annealed NiO/cont-Au/p-GaN sample exhibits ohmic behavior and its specific contact resistance (ρc) is 8.93 × 10−3 Ω cm2. After annealing, Au and NiO contact to GaN individually in the NiO/agg-Au/p-GaN system while the Au and NiO layers become tangled in the NiO/cont-Au/p-GaN system. As a result, the highly tangled NiO-Au structure shall be the key to achieve the ohmic behavior for NiO/cont-Au/p-GaN system.

High Quality Non-Alloyed Pt Ohmic Contacts to P-Type GaN Using Two-Step Surface Treatment

1999 ◽  
Vol 595 ◽  
Author(s):  
Ja-Soon Jang ◽  
Seong-Ju Park ◽  
Tae-Yeon Seong
Keyword(s):  
Surface Treatment ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Transport Mechanisms ◽  
High Quality ◽  
Ammonium Sulfide ◽  
Current Voltage ◽  
Specific Contact ◽  
Thermionic Field Emission ◽  
P Type

AbstractTwo-step surface-treatment is introduced to obtain low resistance Pt contacts to ptype GaN. The first step is performed after the mesa etching process using buffered oxide etch (BOE) and ammonium sulfide [(NH4)2Sx]. This is followed by the second step using BOE. The Pt contact, which was treated sequentially using ultrasonically boiled BOE (10 min) and boiled (NH4)2Sx (10 min), produces a specific contact resistance of 3.0 (±3.8)×10-5 Ωcm2. However, the contact, that was simply BOE-treated, yields 3.1 (±1.1)×10-2 Ωcm2. This indicates that the two-step surface treatment is promising technique for obtaining high quality ohmic contacts to p-GaN. Investigation of the electronic transport mechanisms using current-voltage-temperature (I-V-T) data indicates that thermionic field emission is dominant in the surface-treated Pt contacts.

Microstructure Analysis of Thermally Stable Ohmic Contact to Both n and p+-GaAs

1992 ◽  
Vol 281 ◽  
Author(s):  
W. Y. Han ◽  
H. S. Lee ◽  
Y. Lu ◽  
M. W. Cole ◽  
L. M. Casas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ohmic Contact ◽  
Auger Electron ◽  
Specific Contact Resistance ◽  
Thermally Stable ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Specific Contact ◽  
Electron Spectrometry

ABSTRACTA thermally stable Pd/Ge/Ti/Pt/ ohmic contact with low specific contact resistance was formed on both n and p+-GaAs. The lowest specific contact resistances were 4.7×10−7 and 6.4×10−7 Ω.cm2 for the n and p+-GaAs, respectively, when the n-GaAs was doped with Si to 2×1018cm−3, and the p+-GaAs was doped with carbon to 5×1019 cm−3. Interfacial reactions and element diffusions of the contacts were investigated by using transmission electron microscopy, Auger electron spectrometry with depth profiles. All the contacts were thermally stable at 300 °C for 20 hours, and it appeared that the p-contacts were more stable than the n-contacts.

Dual Role of Tin Reaction Barrier in Gold-Based Metallization to GaAs

1993 ◽  
Vol 300 ◽  
Author(s):  
A. Piotrowska ◽  
E. Kaminska ◽  
M. Guziewicz ◽  
S. Kwiatkowski ◽  
A. Turos
Keyword(s):  
Magnetron Sputtering ◽  
Contact Resistance ◽  
Ohmic Contact ◽  
Diffusion Barrier ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Tin Films ◽  
Specific Contact ◽  
Tin Diffusion Barrier

ABSTRACTThe formation of ohmic contacts to p-GaAs based on Au-Zn system comprising a TiN diffusion barrier has been investigated using 2 MeV He+ RBS and the specific contact resistance measurements. It has been proved that TiN films deposited by reactive RF bias magnetron sputtering serves two purposes. First it suppresses the arsenic evaporation and thus confines the reaction between AuZn and GaAs. Second, it prevents intermixing between p-GaAs/Au(Zn) ohmic contact and an overlayer of Au.

Improved Low Resistance Contacts of Ni/Au and Pd/Au to P-Type GaN Using a Cryogenic Treatment

1999 ◽  
Vol 595 ◽  
Author(s):  
Mi-Ran Park ◽  
Wayne A. Anderson ◽  
Seong-Ju Park
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Cryogenic Treatment ◽  
Microstructural Analysis ◽  
Chemical Vapor ◽  
Specific Contact Resistance ◽  
Mixed Gas ◽  
Low Resistance ◽  
Specific Contact ◽  
P Type

AbstractA low resistance Ohmic contact to p-type GaN is essential for reliable operation of electronic and optoelectronic devices. Such contacts have been made using Ni/Au and Pd / Au contacts to p-type Mg-doped GaN (1.41×1017 cm−3) grown by metalorganic chemical vapor deposition ( MOCVD ) on ( 0001 ) sapphire substrates. Thermal evaporation was used for the deposition of those metals followed by annealing at temperatures of 400 ∼ 700 °C in an oxygen and nitrogen mixed gas ambient, then subsequently cooled in liquid nitrogen which reduced the specific contact resistance from the range of 9.46∼2.80×10−2 ωcm2 to 9.84∼2.65×10−4 ωcm2 for Ni/Au and from the range of 8.35∼5.01×10−4 ωcm2 to 3.34∼1.80×10−4 ωcm2 for Pd/Au. The electrical characteristics for the contacts were examined by the current versus voltage curves and the specific contact resistance was determined by use of the circular transmission line method (c-TLM). The effects of the cryogenic process on improving Ohmic behavior (I-V linearity) and reducing the specific contact resistance will be discussed from a microstructural analysis which reveals the metallurgy of Ohmic contact formation.

NIIN As an Ohmic Contact to P-GAN

1998 ◽  
Vol 537 ◽  
Author(s):  
D. B. Ingerly ◽  
Y. A. Chang ◽  
Y. Chen
Keyword(s):  
Solid State ◽  
Intermetallic Compound ◽  
Contact Resistance ◽  
Ohmic Contact ◽  
Schottky Barrier Height ◽  
Rf Sputtering ◽  
Specific Contact Resistance ◽  
Transmission Line Model ◽  
Specific Contact ◽  
Compound Target

AbstractBased on the criteria for the solid state exchange reaction with p-GaN, we have investigated the intermetallic compound Niln as a possible ohmic contact. The contacts were fabricated by depositing Niln on p-GaN films (p ∼ 2 × 1017 cm-3) using RF sputtering from a compound target. The as-deposited, Niun contacts were found to be rectifying and using I-V characterization a Schottky barrier height of 0.82 eV was measured. Rapid thermal annealing of the contacts was shown to significantly decrease their resistance, with contacts annealed at 800°C for I min yielding the lowest resistance. When annealed at 800°C for 1 min Niln contacts exhibited a specific contact resistance of 8-9 × 10-3 Ωcm2, as measured by the circular transmission line model. To allow a more universal comparison the more traditional Ni/Au contacts, processed under the same conditions, were used as a standard. Their measured specific contact resistance (ρc = 1.2 - 2.1 x 10-2 Ωcm2) was significantly higher than that of the Niln contacts. Demonstrating that Niln has promise as an ohmic contact to p-GaN and should be studied in greater detail.

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