Ion beam processing of MgO thin films

Ide‐Ektessabi, Ari; Nomura, Hiroshi; Yasui, Nobuto; Tsukuda, Yuji

doi:10.1016/s0040-6090(03)01092-7

Cited by 18 publications

(8 citation statements)

References 12 publications

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“…A similar u-2u scan for the MgO/GaAs film revealed only the h1 0 0i oriented growth of MgO. Many research groups reported these kind of observations for various substrates Si h1 1 1i and NaCl h1 0 0i [91], Si h1 0 0i, Pt/Si and SiO 2 /Si [85], and Si and glass [11]. However, growth orientations were not as reported by Stampe.…”

Section: Structural Characterizationsupporting

confidence: 55%

“…In an IBAD system, MgO films can be processed from highpurity MgO pellets with oxygen ion irradiation using an electron cyclotron resonance type ion source [11]. The energy of the ion beam and the deposition rate of MgO are the key control factors to produce various kinds of samples.…”

Section: Ion Beam Assisted Deposition (Ibad)mentioning

confidence: 99%

“…Further, the h1 1 1i peak center shifts to a larger angle and the FWHM of the h1 1 1i peak decreases greatly, indicating a considerable decrease of defect density in the films. Ide-Ektssabi et al [11] suggested the iron beam irradiation during film growth strongly influence the crystal properties. Yu et al [12] showed the role of different assisted ion species in the preferred orientation of the deposited MgO films.…”

Section: Structural Characterizationmentioning

confidence: 99%

“…The influence of the assisting ion beam energy and the deposition rate on density and composition of the films was explained [11]. It was observed that the relative concentration of oxygen increased according to the ion beam energy.…”

Section: Chemical Compositionmentioning

confidence: 99%

See 3 more Smart Citations

Fabrication techniques and material properties of dielectric MgO thin films—A status review

Raj¹,

Jayachandran

Sanjeeviraja

2010

CIRP Journal of Manufacturing Science and Technology

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Section: Structural Characterizationsupporting

confidence: 55%

Section: Ion Beam Assisted Deposition (Ibad)mentioning

confidence: 99%

Section: Structural Characterizationmentioning

confidence: 99%

Section: Chemical Compositionmentioning

confidence: 99%

See 2 more Smart Citations

Fabrication techniques and material properties of dielectric MgO thin films—A status review

Raj¹,

Jayachandran

Sanjeeviraja

2010

CIRP Journal of Manufacturing Science and Technology

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“…Table I shows that the O/Mg ratios of both MgO films are higher than 1, which agrees with the results of previous studies. 19,20 The O/Mg ratio of the MgO film with introducing oxygen is considerably higher than that of the sample without oxygen introduced. The excess oxygen ions in the oxygen-introduced MgO shall occupy the interstitial positions in the MgO lattice or present at grain boundaries.…”

mentioning

confidence: 99%

Improvement of Mobility in ZnO Thin Film Transistor with an Oxygen Enriched MgO Gate Dielectric

Chen

Jeng

Chen

2012

ECS Solid State Letters

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The performance of bottom-gate ZnO thin film transistors (TFTs) using MgO gate dielectrics evaporated with and without introducing oxygen have been investigated. The oxygen introduced during MgO deposition improves the field-effect mobility significantly as compared to the device without introducing oxygen during MgO deposition. The oxygen-introduced MgO exhibits a dielectric constant of 10.9 and the field-effect mobility of the TFT device is enhanced to 78.3 cm 2 /V s. The threshold voltages can also be related to whether the oxygen is introduced into MgO or not. The interface between oxygen-introduced MgO and ZnO is examined and its connection with mobility enhancement is discussed. © 2012 The Electrochemical Society. [DOI: 10.1149/2.003205ssl] All rights reserved. Oxide semiconductor-based thin film transistors (TFTs) as a replacement for conventional Si-based TFTs in electrical and optical devices have been extensively studied due to their excellent optical and electrical properties.1-3 Among the numerous oxide semiconductors, ZnO has been widely used as channel layer in TFTs in recent years, 4-6 owing to its simple composition and expeditious fabrication. In order to accumulate a sufficient number of charges in the TFTs channel, the use of high-dielectric constant (k) materials is suggested, which leads to a reduction in the operating voltage.7-9 Magnesium oxide (MgO) is a candidate of high-k gate dielectrics (k = 9.4∼9.8) 10,11 because of its good isolation 10,12 and chemically inert properties. In addition, MgO films can sustain the plasma damage effectively because it is well-known as an excellent protecting layer of a plasma display panel (PDP) from erosion by plasma ion bombardment. 13,14 Many researches indicate that MgO can play a significant role in controlling the polarity of ZnO film.15-17 Additionally, TFT device parameter such as field effect mobility is mostly related to the crystallinity and defect density of the channel materials. In general, MgO films can possess a large number of excess oxygen ions. 18 In this work we attempted to utilize these excess oxygen ions to compensate for the defect density, such as oxygen vacancies in the channel material. Therefore, MgO thin films that served as gate dielectric in ZnObased TFTs were prepared with and without introducing oxygen by electron beam evaporation. The material and electrical characteristics of the MgO gate dielectrics for the ZnO-based TFTs are investigated to explore the function of the MgO dielectric.The bottom-gate, top contact TFT devices were fabricated on glass substrates. Prior to the MgO deposition, an Al gate electrode was first deposited by electron beam evaporation onto a glass substrate through a shadow mask. MgO films were then deposited with a thickness of 180 nm by electron beam evaporation from the MgO slugs (Kurt J. Lesker, 99.99% purity) with and without introduction of an O 2 gas flow of 50 sccm. The ZnO active layer of a 30 nm thick was deposited on the MgO dielectric by sputtering from a ZnO target (Elecmat, 99.995% ...

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