A novel sputtering technique: Inductively Coupled Impulse Sputtering (ICIS)

Sputtering magnetic materials with magnetron based systems has the disadvantage of field quenching and variation of alloy composition with target erosion. The advantage of eliminating magnetic fields in the chamber is that this enables sputtered particles to move along the electric field more uniformly. Inductively coupled impulse sputtering (ICIS) is a form of high power impulse magnetron sputtering (HIPIMS) without a magnetic field where a high density plasma is produced by a high power radio frequency (RF) coil in order to sputter the target and ionise the metal vapour. In this emerging technology, the effects of power and pressure on the ionisation and deposition process are not known. The setup comprises of a 13.56 MHz pulsed RF coil pulsed with a duty cycle of 25 %. A pulsed DC voltage of 1900 V was applied to the cathode to attract Argon ions and initiate sputtering. Optical emission spectra (OES) for Cu and Ti neutrals and ions at constant pressure show a linear intensity increase for peak RF powers of 500 W – 3400 W and a steep drop of intensity for a power of 4500 W. Argon neutrals show a linear increase for powers of 500 W – 2300 W and a saturation of intensity between 2300 W – 4500 W. The influence of pressure on the process was studied at a constant peak RF power of 2300 W. With increasing pressure the ionisation degree increased. The microstructure of the coatings shows globular growth at 2.95×10−2 mbar and large-grain columnar growth at 1.2×10−1 mbar. Bottom coverage of unbiased vias with a width of 0.360 μm and aspect ratio of 2.5:1 increased from 15 % to 20 % for this pressure range. The current work has shown that the concept of combining a RF powered coil with a magnet-free high voltage pulsed DC powered cathode is feasible and produces very stable plasma. The experiments have shown a significant influence of power and pressure on the plasma and coating microstructure

Nickel coatings by Inductively Coupled Impulse Sputtering (ICIS)

Inductively Coupled Impulse Sputtering (ICIS) removes the need for a magnetron, whilst delivering equal or higher ion-to-neutral ratios compared to other ionised PVD technologies such as High Power Impulse Magnetron Sputtering (HIPIMS). This is especially advantageous for the sputtering of magnetic materials, as these would shunt the magnetic field of the magnetron, thus reducing the efficiency of the sputtering and ionisation process. ICIS produces highly ionised metal-dominated plasma inside a high power pulsed RF-coil with a magnet free high voltage pulsed DC powered cathode. ICIS operation with magnetic target materials has not been attempted so far. The paper aims to clarify the effects of power and pressure on the chemistry of the deposition flux and is the first investigation of the microstructure of ICIS deposited coatings. Modelling based on the intensity of the optical emission spectra (OES) is conducted for the first time on the excited species of Ni and Ar in relation to the applied RF-power. Sputtered species show a linear intensity increase for increasing peak RF-power and constant process gas pressure. The influence of increasing process gas pressure on the ionisation was studied at a constant peak RF-power for pressures. For pressures below 8 Pa the intensity rises, but then remains constant for pressures up to 26 Pa. The microstructure of Ni coatings shows columnar dendritic or globular growth depending on the ionisation degree. In relation to the film thickness on the top of the substrate, the bottom coverage of unbiased vias with an aspect ratio of 4:1 was 15% and for lower aspect ratios of 1.5:1 was 47.5%. The current work has shown that the concept of combining a pulsed RF driven coil with a magnet-free pulsed DC powered cathode works well for the sputtering of magnetic material in a stable plasma

<シリーズ「語りえぬものを問う」＞語りえぬものを問うⅠ「エドガール・モランと現在あるものの社会学」報告 : 市民と専門家の協働としての社会調査

シリーズ「語りえぬものを問う」国際シンポジウム語りえぬものを問うⅠ－エドガール・モランと現在あるものの社会学S’interroger sur l’impliciteⅠ－Edgar Morin et la sociologie du présent2005年9月25日（日）関西学院大学西宮上ヶ原キャンパス関西学院会