In this paper a preparation method for high moment CoFe thin films with soft magnetic properties is reported. A full control of coercivity in a series of 20-nm-thick CoFe films has been achieved without using seed layers, additives, or thermal annealing. The films were sputtered directly onto Si substrates and the coercivity was varied by changing the mean grain size in the sputtered films. The mean grain size was in turn controlled via the sputtering rate. A reduction in the coercivity has been observed from 120Oe for samples with a mean grain size larger than 17nm down to 12Oe for a sample with a mean grain size of 7.2nm. The results are in good agreement with the “random anisotropy model” relating the coercivity to the mean grain size in polycrystalline ferromagnetic films.

Difficulties in controlling the grain size and size distribution in polycrystalline thin films are a major obstacle in achieving efficient performance of thin film devices. In this paper we describe a sputtering technology that allows the control of the grain size and size distribution in sputtered films without the use of seed layers, substrate heating or additives. This is demonstrated for three different materials (Cr, NiFe and FeMn) via transmission electron microscopy imaging and grain size analysis performed using the cumulative percentage method. The mean grain size was controlled only via the sputtering rate. We show that higher sputtering rates promote the growth of larger grains. Similar trends were obtained in the standard deviation, which showed a clear reduction with the sputtering rate.

Amorphous hafnium oxide ͑HfO x ͒ is deposited by sputtering while achieving a very high k ϳ 30. Structural characterization suggests that the high k is a consequence of a previously unreported cubiclike short range order in the amorphous HfO x ͑cubic k ϳ 30͒. The films also possess a high electrical resistivity of 10 14 ⍀ cm, a breakdown strength of 3 MV cm −1 , and an optical gap of 6.0 eV. Deposition at room temperature and a high deposition rate ͑ϳ25 nm min −1 ͒ makes these high-k amorphous HfO x films highly advantageous for plastic electronics and high throughput manufacturing.

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Abstract:Tin doped indium oxide (ITO) has been directly deposited onto a variety of flexible materials by a reactive sputtering technique that utilises a remotely generated, high density plasma. This technique, known as high target utilisation sputtering (HiTUS), allows for the high rate deposition of good quality ITO films onto polymeric materials with no substrate heating or post deposition annealing. Coatings with a resistivity of 3.8 ×10−4 Ωcm and an average visible transmission of greater than 90% have been deposited onto PEN and PET substrate materials at a deposition rate of 70 nm/min. The electrical and optical properties are retained when the coatings are flexed through a 1.0 cm bend radius, making them of interest for flexible display applications.

A novel rf sputtering technology in which a high density plasma is created in a remote chamber has been used to reactively deposit zinc oxide (ZnO) and indium zinc oxide (IZO) thin films at room temperature from metallic sputtering targets at deposition rates ∼50 nm min −1 , which is approximately an order of magnitude greater than that of rf magnetron sputtering. Thin film transistors have been fabricated using IZO with a maximum processing temperature of 120 • C, which is defined by the curing of the photoresist used in patterning. Devices have a saturated field effect mobility of 10 cm 2 V −1 s −1 and a switching ratio in excess of 10 6 . Gate bias stress experiments performed at elevated temperatures show a consistent apparent increase in the field effect mobility with time, which is attributed to a charge trapping phenomenon.

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Abstract-In this paper, we present a description of a novel high-rate plasma sputtering system that allows the control of grain size in sputtered films. Additionally, the system has the advantage of a better utilization of the target material (around 80% to 90%) by eliminating the race track at the target as in conventional plasma magnetron sputtering systems. The potential and capabilities of this novel plasma sputtering device are demonstrated in this paper by the deposition of a number of different Cr thin films suitable for underlayers in thin-film media and for which we have performed a systematic X-ray and TEM analysis to determine the grain-size histograms, mean grain diameters, and their relationship to the sputtering processes.