Papers by Keyword: Ohmic Contact

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Authors: Jun Kajihara, Shinichiro Kuroki, Seiji Ishikawa, Tomonori Maeda, Hiroshi Sezaki, Takahiro Makino, Takeshi Ohshima, Mikael Östling, Carl Mikael Zetterling
Abstract: 4H-SiC pMOSFETs with Al-doped S/D and NbNi silicide ohmic contacts were demonstrated and were characterized at up to a temperature of 200 °C. For the pMOSFETs, silicides on p-type 4H-SiC with Nb/Ni, NbNi alloy, Ni and Nb/Ti were investigated, and the Nb/Ni silicide with the contact resistance of 5.04×10-3 Ωcm2 were applied for the pMOSFETs.
Authors: K. Gottfried, H. Fritsche, J. Kriz, J. Leibelt, C. Kaufmann, F. Rudolf, T. Gessner
Authors: A. Kestle, S.P. Wilks, P.R. Dunstan, M. Pritchard, G. Pope, A. Koh, Philip A. Mawby
Authors: Soo Chang Kang, Moo Whan Shin
Authors: Francesco Moscatelli, Andrea Scorzoni, Antonella Poggi, G.C. Cardinali, Roberta Nipoti
Authors: Roberta Nipoti, Anders Hallén, Antonella Parisini, Francesco Moscatelli, Salvatore Vantaggio
Abstract: The p-type doping of high purity semi-insulating 4H-SiC by Al+ ion implantation and a conventional thermal annealing of 1950 °C/5 min has been studied for implanted Al concentration in the range of 1 x1019 - 8 x 1020 cm-3 (0.36 μm implanted thickness). Sheet resistance in the range of 1.6 x 104 to 8.9 x102 Ω, corresponding to a resistivity in the range of 4.7 x 10-1 to 2.7 x 10-2 Ωcm for increasing implanted Al concentration have been obtained. Hall carrier density and mobility data in the temperature range of 140–600 K feature the transition from a valence band to an intra-band conduction for increasing implanted Al concentration. The specific contact resistance of Ti/Al contacts on the 5 x1019 cm-3 Al implanted specimen features a thermionic field effect conduction with a specific contact resistance in the 10-6 Ωcm2 decade.
Authors: Lilyana Kolaklieva, V. Chitanov, Roumen Kakanakov
Abstract: Al-Free Nanolayered Metallizations Based on the Transition Metals Ti, Mo, Ni and Pd, with Varied Ti Content, Have Been Developed as an Alternative of the Al-Based Contacts for Sub-Micron Hemts. the Electrical, Morphological and Thermal Properties of the Metallization Schemes Have Been Studied with the Aim of Obtaining the Most Suitable Combination of Low Resistivity, a Smooth Surface and an Acute Edge. the Lowest Resistivity of 8.8x 10-6 Ω.cm2 Has Been Determined with the Ti/Mo/Ti/Au Contact, while the Lowest Surface Roughness of 6 Nm Has Been Measured for the Ti/Ni/Ti/Au Metallization. these Contact Schemes Have Shown much Better Edge Acuity in Comparison to the Al-Based Metallizations.
Authors: Nicolas Thierry-Jebali, Olivier Ménard, Arnaud Yvon, Emmanuel Collard, Miao Zhe, Olivier Dezellus, Christian Brylinski, Jean Claude Viala
Abstract: Ohmic contacts represent a major technological brick for the development of high power devices on Gallium Nitride. Al(200 nm) Ti(70 nm) metallization on n+-GaN, annealed at 650 °C, provides a “Specific Contact Resistivity” (SCR) in the range mid 10-5 Ω.cm², which is low enough for the main switching power applications. However, the Al-Ti metallic compound phases formed during the annealing step result from solid-solid reactions, which may lead to high stress and / or poor cohesion, possibly deleterious to contact reliability. In this work, we have investigated several configurations of Ti-Al-Si based contacts, aiming at favoring liquid-solid reactions and / or Si element diffusion, in order to get better SCR and / or morphology and cohesion of the metallic phase. Surprisingly, only contacts annealed at low temperature (450 °C) provide low contact SCR, comparable to that of Ti-Al only contact, but systematically higher.
Authors: Bharat Krishnan, Siva Prasad Kotamraju, Galyna Melnychuk, Neil Merrett, Yaroslav Koshka
Abstract: Low-temperature halo-carbon homoepitaxial growth is suitable for selective epitaxial growth of 4H-SiC using SiO2 mask. A possibility of achieving high values of doping in combination with the selective growth makes it an alternative to ion implantation for selective doping in SiC. In this work, TMA doping in situ during a blanket low-temperature epitaxial growth was utilized to produce heavily Al doped SiC layers for Ohmic contact formation to p-type SiC. Nearly featureless epilayer morphology with Al atomic concentration exceeding 3x1020 cm-3 was obtained after growth at 13000C with the growth rate of 1.5 µm/hr. Ni TLM contacts with a thin adhesion layer of Ti were formed. The as-deposited metal contacts were almost completely Ohmic even before annealing. The specific contact resistance of 2x10-2 Ohm-cm2 and 6x10-5 Ohms-cm2 was achieved without and with contact annealing respectively. The resistivity of the epitaxial layers better than 0.01 Ohm cm was measured for Al atomic concentration of 2.7x1020 cm-3.
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