Bimodal substrate biasing to control γ-Al₂O₃ deposition during reactive magnetron sputtering

Abstract

Al 2 O 3 thin films have been deposited at substrate temperatures between 500• C to 600• C by reactive magnetron sputtering using an additional arbitrary substrate bias to tailor the energy distribution of the incident ions. The films were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR).The film structure being amorphous, nanocrystalline, or crystalline was correlated with characteristic ion energy distributions. The evolving crystalline structure is connected with different levels of displacements per atom (dpa) in the growing film as being derived from TRIM simulations. The boundary between the formation of crystalline films and amorphous or nanocrystalline films was at 0.9 dpa for a substrate temperature of 500 • C. This threshold shifts to 0.6 dpa for films grown at 550 • C.

Effect of radio-frequency substrate bias on ion properties and sputtering behavior of 2 MHz magnetron sputtering

“…These results are not completely agreement with the usual idea, that is the role of substrate bias is to enhance the ionic bombardment [14,15,17,18]. However, the variation of IVDFs with substrate bias and discharge pressure is well agreement with other works [19][20][21]34]. Because the substrate bias leads to not only the divergence of ions energy but also the increase of ions flux density to the substrate, the increase of ions bombarding on the grown films should be related to the energy density onto the substrate, depended on both the ions energy distribution and the ions flux density.…”

“…Because many works were mainly paid attentions to the correlation between the substrate bias and the structure and property of films, and lacking of the detail investigation on ions behavior, it is generally thought that the role of substrate bias is to enhance the ionic bombardment [14,15,17,18]. However, some works thought that the ion bombardment is determined by the ion energy distribution (IED) because the ion energy is influenced by the collisions in the substrate sheath [19,20]. In addition, the simulation and experimental measurement also supported that the RF substrate bias had more effect on the IED at the substrate [21][22][23].…”

Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

“…In general, the RFEA measurements indicate how the IEDF can be controlled by driving a CCRF discharge with customized voltage waveforms, which is an important result for applications. 61,[88][89][90] By varying the phase the mean ion energy can be controlled. The mean value for the mean ion energy with two consecutive harmonics is 64 eV and can be varied by 35%, while the flux varies by 615 %.…”

Дуговое Напыление Покрытий На Основе Оксида Алюминия В Элионном Режиме

“…Однако, оксид алюминия является диэлектриком, что осложняет использование такого метода ускорения ионов. Частично эта проблема решается при подаче импульсного смещения [16] [19,20].…”