Fundamental characteristics of built-in high-frequency coil-type sputtering apparatus

Abstract

A high-rate sputtering apparatus designed for ion-based film formation was made on an experimental basis. A dense plasma of the order of 1012 cm−3 was generated between the target and the substrate of a dc diode sputtering apparatus by means of an L-coupled high-frequency discharge. When a Cu target was used, the Cu+ ion current in the mass spectrum of the extracted ion beam increased with the Ar gas pressure, and had a maximum value about ten times that of an Ar+ ion current, at a pressure of ∼1×10−1 Torr (1.3×101 Pa). The plasma potential varied continuously from +20 to +200 V when the bias resistance for the high-frequency coil was changed from 10 kΩ to 0. The energy of the ions impinging on the substrate was changed greatly by the change in the plasma potential. The fine structure of the film formed was markedly influenced by the discharge gas pressure and/or the plasma potential. Even ferromagnetic material could be sputtered at a high rate.

Design and characterization of an RF plasma cleaner

“…Therefore, we have that Γ sputt Γ e ≈ Γ i Γ n . From this results we conclude that the contamination of the sample by sputtered material from the antenna is not substantial, confirming the experimental result obtained by Yamashita [5]. For a steady state condition, we take t → ∞ and plot the density of impurities as function of position inside the reactor, which is shown in figure 3.…”

“…This is discussed in the next section, together with the model to calculate the spatial distribution of the impurities generated by sputtering of the antenna. As found in the literature [5], we show that the level of impurities is negligible at the position where the substrate is placed. The experimental set up is presented in Section 3 and the characterization of the discharge in Section 4.…”

“…Yamashita [5] has shown experimentally that in a similar system the sample contamination could be disregarded. To address this problem, we developed a theoretical model to study the spatial distribution of the impurity density in the plasma, due to erosion of the antenna.…”

“…This is usually a small vacuum chamber in which the plasma is produced by an inductive-coupled RF discharge, with the antenna placed outside the vacuum chamber [5]. This scheme avoids the plasma contamination observed in capacitively coupled discharges, widely used in the electronic industry, due to erosion of the electrodes inside the vacuum chamber [6].…”

Investigations of Production Processes of Ti+in High-Pressure Magnetron Sputtering Plasmas

“…To overcome this problem, ionized physical vapor deposition (IPVD) has been proposed and studied intensively. [1][2][3][4][5][6][7][8][9] In IPVD, metal atoms produced from a target are ionized in the sputtering plasma, and metal ions are accelerated toward the bottom of fine patterns by the sheath electric field between the plasma and the substrate. This enables directional deposition, resulting in a deposition profile with a high bottom coverage inside fine trenches and holes with high aspect ratios.…”