Deposition of Aluminum-Doped ZnO Films by ICP-Assisted Sputtering

Self Cite

To understand the deposition mechanism during the inductively coupled plasma (ICP) assisted DC magnetron sputter-deposition of transparent conductive Al-doped ZnO (AZO) films, energy flux to a substrate was investigated. The total energy flux to a substrate (Jtotal) was measured by two types of thermal probes: one for the absolute value measurement of Jtotal at a fixed position, and the other for the spatial distribution measurement of Jtotal. The contribution due to charged species (Jch) was evaluated by the Langmuir probe measurements of plasma parameters. As a result, it was found that i) Jtotal was about 3000 W m−2 for the typical deposition condition and this value was about one order of magnitude larger than those of conventional planar magnetron sputtering, and ii) most of Jtotal was contributed by plasma charged species.

Section: Spatial Profile Of J Total Measured With a Compact Tp2mentioning

confidence: 99%

Measurement of energy flux to a substrate by thermal and Langmuir probes during inductively coupled plasma assisted DC magnetron sputtering

Matsuda

Mine

Wakiyama

et al. 2014

Self Cite

“…Indium-free metal-doped zinc oxide, Ga− or Al-doped ZnO (GZO, AZO) is attractive as an environmentally friendly transparent conductive oxide and is expected to be one of the candidates to replace ITO. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] A problem with planar magnetron sputter deposition using oxide targets is that the film composition and crystallinity on the substrate surface opposite the eroded area of the target is reduced. This has multiple causes.…”

Section: Introductionmentioning

confidence: 99%

Energy distribution function of substrate incident negative ions in magnetron sputtering of metal-doped ZnO target measured by magnetized retarding field energy analyzer

Matsuda,

Watanabe,

Uzunoe

et al. 2023

The energy distribution function of the substrate incident negative ions during magnetron sputtering of a metal-doped zinc oxide target was measured using a home-made retarding field energy analyser (RFEA) with a magnetic field region.The cross-field region in front of the RFEA injection aperture allows the bulk electrons in the plasma into the RFEA are dramatically suppressed, while the inflow of negative ions emitted from the oxide target is largely unaffected. Negative ions were found to be mainly emitted from the target erosion region, accelerated by the potential difference between the target and the substrate, and injected as a high-energy beam onto the opposite substrate. Compared to energy-resolved mass spectrometers, which require differential pumping and are large and not very portable, magnetised RFEA is inexpensive, compact and easy to sweep in space, although there is no mass separation.

“…Numerous studies have been conducted so far to overcome these problems with the goal of substituting ITO with metal-doped ZnO. To further lower the resistivity and flatten the resistivity spatial distribution, it is reported that the following are effective: addition of hydrogen gas, 13,14) substrate heating during film formation, 15,16) post annealing, 17) formation of an intermediate buffer layer between thin film and substrate, [18][19][20] off-axis arrangement of substrate, 21) use of facing targets, 22,23) superposition of DC and RF, 16,[24][25][26] utilization of inductively coupled plasma assist, [27][28][29] installation of mesh grid between target and substrate, 30) etc.…”

Section: Introductionmentioning

confidence: 99%

Reduction and uniformization of the resistivity of Ga-doped ZnO by combining short-gap magnetron sputtering and buffer layer

Matsuda¹,

Matsuo²,

Sakamoto³

et al. 2019

To obtain low-resistance metal-doped ZnO film with a uniform resistivity distribution, a combination of short-gap magnetron sputtering and a buffer layer is proposed. The influence of the distance between the target and the substrate (T-S distance) on properties such as the thickness, resistivity, carrier density, carrier mobility, and crystallinity of Ga-doped ZnO thin films deposited by conventional RF planar magnetron sputtering was investigated. As the T-S distance decreased, the film resistivity remarkably decreased. Although spontaneous annealing greatly reduced the film's resistivity, the opposing part of the target erosion area showed high resistivity, possibly due to the bombardment of oxygen negative ions. The spatial uniformity in resistivity was greatly improved using a glass substrate on which a solid-phase-crystallized thin buffer layer was formed.