scholarly journals Improved Electrical Characteristics of 1200V/20A 4H-SiC Diode by Substrate Thinning and Laser Annealing

2021 ◽  
Vol 2083 (2) ◽  
pp. 022094
Author(s):  
Qianqian Jiao ◽  
Tao Zhu ◽  
Hang Zhou ◽  
Qingling Li
Keyword(s):  
Silicon Carbide ◽  
Ohmic Contact ◽  
Laser Annealing ◽  
Annealing Process ◽  
Electrical Characteristics ◽  
Medium Voltage ◽  
Rapid Annealing ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Statistical Results

Abstract In this paper, two kinds of silicon carbide (SiC) backside metallization processes were developed, which were backside thinning combined with laser annealing to form ohmic contact and direct rapid annealing (RTA) to form ohmic contact. The specific contact resistivity obtained by both annealing processes was 3.4E-5 Ω·cm2 to 3.8E-5 Ω·cm2. In order to obtain the effect of thinning combined with laser annealing process on forward conduction characteristics of medium voltage devices,1200V/20A JBS diode was developed, and the backside contact adopted the above two annealing schemes, the thickness of 4H-SiC substrate is 200μm. According to the statistical results of hundreds of JBS diodes, the electrical characteristics of the two types JBS are basically the same. Compared with the JBS diode without substrate thinning, the forward conduction voltage (VF) of the thinned JBS diode is decreased about 0.048V. When the substrate of 1200V SiC JBS diodes is reduced to 80μm, the value of VF can only be reduced by about 0.0868V.

Effects of Surface and Interlayer Processing Conditions on Selected Ohmic Contact Metallizations for p-type Silicon Carbide

2000 ◽  
Vol 640 ◽  
Author(s):  
L. M. Porter ◽  
T. Jang ◽  
T. Worren ◽  
K. C. Chang ◽  
N. A. Papanicolaou ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Surface Morphology ◽  
Ohmic Contact ◽  
Deposition Temperature ◽  
Doping Concentration ◽  
Processing Conditions ◽  
Dopant Incorporation ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
P Type

ABSTRACTA comparative study of Pt and Pt/Si contacts to p-type 6H-SiC in terms of various processing conditions and interlayer specifications was performed. Deposition temperature, the thickness of the Si layer, and B-dopant incorporation in the Si were found to significantly affect the specific contact resistivity (SCR) values. In addition, pre-etching of the SiC surface in SF6 + Ar was found to consistently reduce the SCR's. The lowest average SCR values were 3 × 10−5 Ωcm2 for Pt/Si/SiC contacts deposited on pre-etched SiC surfaces (7.0 × 1018 cm−3 doping concentration) and annealed at 1100 °C for 5 min.Aluminum-titanium contacts also showed dependence on the thicknesses of the Al and Ti layers and on the locations of the layers. Differences in both the SCRs and surface morphology are presented.

Low specific contact resistivity to graphene achieved by AuGe/Ni/Au and annealing process

2016 ◽  
Vol 25 (11) ◽  
pp. 118101
Author(s):  
Shu-Zhen Yu ◽  
Yan Song ◽  
Jian-Rong Dong ◽  
Yu-Run Sun ◽  
Yong-Ming Zhao ◽  
...  
Keyword(s):  
Annealing Process ◽  
Contact Resistivity ◽  
Specific Contact ◽  
Specific Contact Resistivity

Contact Resistivity of NiPtSi on n-doped Silicon Activated by Laser Annealing

2008 ◽  
Vol 1108 ◽  
Author(s):  
Francois Pagette ◽  
Paul M Solomon ◽  
Paul M Kozlowski ◽  
Anna W Topol ◽  
Wilfried Haensch
Keyword(s):  
Laser Annealing ◽  
Low Voltage ◽  
Contact Resistivity ◽  
Experimental Methodology ◽  
Rapid Thermal Anneal ◽  
Device Structure ◽  
Zero Bias ◽  
Doped Silicon ◽  
Specific Contact ◽  
Specific Contact Resistivity

AbstractReducing specific contact resistivity of the silicide to silicon interface is advantageous to achieve high planar density and high drive current FET devices. Measuring the differential resistivities at different low voltage bias conditions of four terminal Kelvin test structures with a range of contact sizes has proven particularly effective in characterizing the linearity behavior and specific contact resistivity. This study shows that adding laser activation annealing for an n+ doped silicon contacted by a standard NiPt silicide is found to significantly improve the contact electrical properties. Initial results with only rapid thermal anneal activation show a size dependence of the contact resistivity with non-linear behavior exhibiting maximum resistance at zero bias, and contact resistivities ranging from 4×10-8 Ω-cm2 to 4×10-7 Ω-cm2. Adding laser anneal after the rapid thermal anneal gives ohmic behavior, for contact down to 50nm in size, with a specific contact resistivity of 1×10-8 Ω-cm2. The metal-to-silicide contact resistance was measured separately using a novel test structure and it was confirmed to be negligible. We describe our device structure, our experimental methodology, and the implications of our results for future devices.

Thermal Stability of Ohmic Contacts to n-InxGa1−xN

1995 ◽  
Vol 395 ◽  
Author(s):  
A. Duibha ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
J. W. Lee ◽  
P. H. Holloway ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electron Spectroscopy ◽  
Ohmic Contacts ◽  
Electrical Characteristics ◽  
Microstructural Properties ◽  
Excellent Thermal Stability ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Thermal Stability Of

ABSTRACTThe microstructural properties and interdiffusion reactions of Au/Ge/Ni, Ti/Pt/Au, WSix and AuBe contacts on GaN and In0.5Ga0.5N have been examined using Scanning Electron Microscopy and Auger Electron Spectroscopy. The WSix contacts possess excellent thermal stability and retained good structural properties at annealing temperatures as high as 800°C on GaN. The electrical characteristics of WSix contacts on In0.5Ga0.5N had a specific contact resistivity of 1.48×10−5Ωcm2 and an excellent surface morphology following annealing at 700°C. The increase in contact resistance observed at higher temperatures was attributed to intermixing of metal and semiconductor. In contrast the Ti/Pt/Au and Au/Ge/Ni contacts were stable only to ≤ 500°C. AuBe contacts had the poorest thermal stability, with substantial reaction with GaN occurring even at 400°C. The WSix contact appears to be an excellent choice for high temperature GaN electronics applications.

Optimization of Ni/Nb Ratio for High-Temperature-Reliable Ni/Nb Silicide Ohmic Contact on 4H-SiC

2019 ◽  
Vol 963 ◽  
pp. 498-501
Author(s):  
Vuong Van Cuong ◽  
Seiji Ishikawa ◽  
Hiroshi Sezaki ◽  
Tomonori Maeda ◽  
Satoshi Yasuno ◽  
...  
Keyword(s):  
High Temperature ◽  
Ohmic Contact ◽  
Contact Resistivity ◽  
Specific Contact Resistance ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Transfer Length ◽  
Ohmic Behavior ◽  
Specific Contact ◽  
Specific Contact Resistivity

Low specific contact resistivity and high-temperature reliability of the Ni (x)/Nb (100-x) (where x = 25, 50, 75 nm) ohmic contact to 4H-SiC were investigated. After the annealing process at 1000°C for 3 min in N2 ambient, the I-V curves indicated that all the contacts exhibited the ohmic behaviors. Based on the transfer length method, the specific contact resistivity of the contacts were extracted. High concentration of Ni was responsible for low specific contact resistance of the Ni (75)/Nb (25)/4H-SiC sample by the formation of Ni2Si compound after the fabrication process. However, this contact lost the ohmic behavior at low temperature of 150°C. Whereas, both Ni (50)/Nb (50)/4H-SiC and Ni (25)/Nb (75)/4H-SiC contacts remained the ohmic behavior for 100-hour aging at 400°C. Two-dimensional X-ray diffraction analyses showed that the presence of carbon agglomeration formed at the interface of the Ni (75)/Nb (25)/4H-SiC contact caused the degradation of this sample when being aged at high temperature environment. Meanwhile, higher concentration of Nb in the Ni (50)/Nb (50)/4H-SiC and Ni (25)/Nb (75)/4H-SiC samples improved the ability to collect the excess carbon atoms and thus enhanced the high temperature reliability of these contacts when operating in high temperature ambient. Considering both low specific contact resistivity and high temperature reliability, the Ni (50)/Nb (50)/4H-SiC contact can be a good candidate for harsh environment applications.

scholarly journals Effects of Intense Pulsed Light (IPL) Rapid Annealing and Back-Channel Passivation on Solution-Processed In-Ga-Zn-O Thin Film Transistors Array

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 508 ◽  
Author(s):  
Hyun Jae Kim ◽  
Chul Jong Han ◽  
Byungwook Yoo ◽  
Jeongno Lee ◽  
Kimoon Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Field Effect ◽  
Annealing Process ◽  
Intense Pulsed Light ◽  
Electrical Characteristics ◽  
Field Effect Mobility ◽  
Pulsed Light ◽  
Solution Processed ◽  
Rapid Annealing

We report on the effects of the intense pulsed light (IPL) rapid annealing process and back-channel passivation on the solution-processed In-Ga-Zn-O (IGZO) thin film transistors (TFTs) array. To improve the electrical properties, stability and uniformity of IGZO TFTs, the oxide channel layers were treated by IPL at atmospheric ambient and passivated by photo-sensitive polyimide (PSPI). When we treated the IGZO channel layer by the IPL rapid annealing process, saturation field effect mobility and subthreshold swing (S.S.) were improved. And, to protect the back-channel of oxide channel layers from oxygen and water molecules, we passivated TFT devices with photo-sensitive polyimide. The IGZO TFTs on glass substrate treated by IPL rapid annealing without PSPI passivation showed the field effect mobility (μFE) of 1.54 cm2/Vs and subthreshold swing (S.S.) of 0.708 V/decade. The PSPI-passivated IGZO TFTs showed higher μFE of 2.17 cm2/Vs than that of device without passivation process and improved S.S. of 0.225 V/decade. By using a simple and fast intense pulsed light treatment with an appropriate back-channel passivation layer, we could improve the electrical characteristics and hysteresis of IGZO-TFTs. We also showed the improved uniformity of electrical characteristics for IGZO TFT devices in the area of 10 × 40 mm2. Since this IPL rapid annealing process could be performed at a low temperature, it can be applied to flexible electronics on plastic substrates in the near future.

Piezoresistive Sensitivity and Al Ohmic Contact of Highly Doped Polycrystalline Silicon Nano Thin Films

2011 ◽  
Vol 483 ◽  
pp. 789-793
Author(s):  
Chang Zhi Shi ◽  
Xiao Wei Liu ◽  
Xuan Wu ◽  
Hai Tao Zheng
Keyword(s):  
Thin Films ◽  
Ohmic Contact ◽  
Polycrystalline Silicon ◽  
Depletion Region ◽  
Contact Resistivity ◽  
Gauge Factor ◽  
Piezoresistive Effect ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Polycrystalline Silicon Films

The piezoresistive and ohmic contact properties of polycrystalline silicon nano thin films were investigated in this paper. The polycrystalline silicon films with different thicknesses and doping concentrations were deposited by LPCVD and doped with boron highly, and then the cantilever beam samples were fabricated by photolithography and wet etching. By measuring the gauge factor and specific contact resistivity, the specific contact resistivity of Al contacts can reach 2.4×10-3Ω·cm2 after the alloying at 450 °C for 20 min; the enhanced piezoresistive effect of highly doped polycrystalline silicon nano thin films was discovered. The conclusions indicated that the enhanced piezoresistive sensitivity of PNTFs is due to the modification of depletion region barrier by ultra high doping and film thickness thinning and the enhancement of tunneling piezoresistive effect. The distinct piezoresistive phenomenon of PNTFs could be utilized for the development and fabrication of miniature piezoresistive sensors.

scholarly journals Development of an Extreme High Temperature n-Type Ohmic Contact to Silicon Carbide

2012 ◽  
Vol 717-720 ◽  
pp. 841-844 ◽  
Author(s):  
Laura J. Evans ◽  
Robert S. Okojie ◽  
Dorothy Lukco
Keyword(s):  
Heat Treatment ◽  
Silicon Carbide ◽  
Ohmic Contact ◽  
Operating Temperature ◽  
Specific Contact Resistance ◽  
Transfer Length ◽  
Ohmic Behavior ◽  
Contact Metallization ◽  
Extreme High Temperature ◽  
Specific Contact

We report on the initial demonstration of a tungsten-nickel (75:25 at. %) ohmic contact to silicon carbide (SiC) that performed for up to fifteen hours of heat treatment in argon at 1000 °C. The transfer length method (TLM) test structure was used to evaluate the contacts. Samples showed consistent ohmic behavior with specific contact resistance values averaging 5 x 10-4 Ω-cm2. The development of this contact metallization should allow silicon carbide devices to operate more reliably at the present maximum operating temperature of 600 °C while potentially extending operations to 1000 °C.

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