Particle‐in‐Cell/Monte Carlo Collisions Model for the Reactive Sputter Deposition of Nitride Layers

Abstract

A 2d3v Particle‐in‐cell/Monte Carlo collisions (PIC/MCC) model was constructed for an Ar/N2 reactive gas mixture in a magnetron discharge. A titanium target was used, in order to study the sputter deposition of a TiNx thin film. Cathode currents and voltages were calculated self‐consistently and compared with experiments. Also, ion fluxes to the cathode were calculated, which cause sputtering of the target. The sputtered atom fluxes from the target, and to the substrate were calculated, in order to visualize the deposition of the TiNx film.

Characterization of an Ar/O2magnetron plasma by a multi-species Monte Carlo model

“…After the collision, the SP can be lost, or a secondary SP can be created (which is also followed in the calculation), or the SP is scattered from its original path, after which it receives new velocities (direction and magnitude). Details about the post-collision treatment for a magnetron discharge are given in [32,33,39,45]. Note that certain species that are created by these reactions are not followed in the model, since they are not very relevant for the sputter deposition process under the considered conditions [39].…”

“…An electrical circuit, consisting of an external resistance (R ext = 1500 ) and voltage source (V ext = −600 V), is connected to the cathode, whereas the other walls are grounded, to generate an electric field. In our PIC/MCC code, the electric field distribution was self-consistently calculated for a targetsubstrate distance of 24 mm, and it gave rise to a cathode current and voltage of 0.18 A and 320 V, respectively [39,45]. This calculated electric field distribution is used as input in our multi-species MC model.…”

“…The combined model is called the particle-incell/Monte Carlo collisions (PIC/MCC) model. The PIC/MCC models have been developed to study magnetron discharges in pure argon in [27][28][29][30][31][32][33][34][35][36], whereas Ar/N 2 discharges were studied in [37,38], and Ar/O 2 discharges in [39,40].…”

Computer Modeling of Plasmas and Plasma‐Surface Interactions

“…Nevertheless, calculation times can still rise to several weeks for describing magnetron discharges, certainly when some plasma chemistry is included, such as for reactive sputter‐deposition applications. The example illustrated here is a PIC‐MCC simulation applied to a planar dc magnetron, operating in an Ar/N 2 gas mixture with Ti target (cathode), used for the reactive sputter‐deposition of TiN x films 14, 15. In this case, beside electrons also several types of ions (Ar + , N, N + , Ti + ) and fast atoms (Ar f , Ti f , N f ) are described in the PIC‐MCC model.…”