Transport mechanisms of RF sputtered Al-doped ZnO films by H2 process gas dilution

Addonizio, M.L.; Antonaia, A.; Cantele, Giovanni; Privato, C.

doi:10.1016/s0040-6090(99)00186-8

Cited by 100 publications

(57 citation statements)

References 18 publications

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“…The hydrogen will readily diffuse at the treatment temperatures and is a well known source of excess carriers in ZnO:Al films. [53][54][55] In order to clarify this effect, experiments with sputtered SiN layers were carried out and showed, that the increase in carrier concentration is significantly reduced with these hydrogen-free barrier layers. Thus the hydrogen from the SiN layer can be regarded as responsible for a part of the increase in N e .…”

Section: Discussionmentioning

confidence: 99%

Improved electrical transport in Al-doped zinc oxide by thermal treatment

Ruske

Roczen

Lee

et al. 2010

Journal of Applied Physics

176

100

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A postdeposition thermal treatment has been applied to sputtered Al-doped zinc oxide films and shown to strongly decrease the resistivity of the films. While high temperature annealing usually leads to deterioration of electrical transport properties, a silicon capping layer successfully prevented the degradation of carrier concentration during the annealing step. The effect of annealing time and temperature has been studied in detail. A mobility increase from values of around 40 cm2/Vs up to 67 cm2/Vs, resulting in a resistivity of 1.4×10−4 Ω cm has been obtained for annealing at temperatures of 650 °C. The high mobility increase is most likely obtained by reduced grain boundary scattering. Changes in carrier concentration in the films caused by the thermal treatment are the result of two competing processes. For short annealing procedures we observed an increase in carrier concentration that we attribute to hydrogen diffusing into the zinc oxide film from a silicon nitride barrier layer between the zinc oxide and the glass substrate and the silicon capping layer on top of the zinc oxide. Both are hydrogen-rich if deposited by plasma-enhanced chemical vapor deposition. For longer annealing times a decrease in carrier concentration can occur if a thin capping layer is used. This can be explained by the deteriorating effect of oxygen during thermal treatments which is well known from annealing of uncapped zinc oxide films. The reduction in carrier concentration can be prevented by the use of capping layers with thicknesses of 40 nm or more.

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Section: Discussionmentioning

confidence: 99%

Improved electrical transport in Al-doped zinc oxide by thermal treatment

Ruske

Roczen

Lee

et al. 2010

Journal of Applied Physics

176

100

View full text Add to dashboard Cite

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“…Reports on aluminium and fluorine doped films, deposited using sputtering [16] and CSP [17] techniques, respectively, have proved this. Main objective of our work is to investigate the effect of spray rate variation on structural, electrical and optical properties of ZnO thin films.…”

Section: Introductionmentioning

confidence: 89%

On tuning the orientation of grains of spray pyrolysed ZnO thin films

Vimalkumar

Poornima

Kartha

et al. 2010

Applied Surface Science

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a b s t r a c tEffect of varying spray rate on the structure and optoelectronic properties of spray pyrolysed ZnO film is analysed. ZnO films were characterised using different techniques such as X-ray diffraction (XRD), photoluminescence, electrical resistivity measurement, and optical absorption. The XRD analysis proved that, with the increase in spray rate, orientation of the grains changed from (1 0 1) plane to (0 0 2) plane. The films exhibited luminescence in two regions-one was the 'near band-edge' (NBE) (∼380 nm) emission and the other one was the 'blue-green emission' (∼503 nm). Intensity of the blue-green emission decreased after orientation of grains shifted to (0 0 2) plane. Scanning electron microscope (SEM) analysis of the films asserts that spray rate has major role in improving the crystallographic properties of the films. Moreover resistivity of the films could be lowered to 2.4 × 10 −2 cm without any doping or post-deposition annealing.

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“…Mostly, in papers reporting on electrical properties of TCOs either no theoretical explanation at all [1] or only ionized impurity scattering as dominant mobility limitation are given [2,3]. Only few thorough papers dealt with other scattering processes than ionized impurity scattering: Pisarkiewicz et al measured the mobility of CdIn 2 O 4 and SnO 2 thin films as a function of the carrier concentration N [4,5].…”

Section: Introductionmentioning

confidence: 99%