Scaling of hollow cathode magnetrons for ionized metal physical vapor deposition

Abstract

Flux and energy analysis of species in hollow cathode magnetron ionized physical vapor deposition of copper Rev. Sci. Instrum. 81, 123502 (2010); 10.1063/1.3504371 In situ plasma diagnostics study of a commercial high-power hollow cathode magnetron deposition tool Atomistic feature scale modeling of the titanium ionized physical vapor deposition process Ionized metal physical vapor deposition is being increasingly used to deposit diffusion barriers and Cu seed layers into high aspect ratio trenches for microelectronics fabrication. Hollow cathode magnetrons ͑HCMs͒ represent a technology capable of depositing metal over large areas at pressures of a few millitorrs. The fundamental mechanisms of these devices are not well understood and so their optimization is difficult. In this article, results from a two-dimensional computational investigation of HCMs are discussed to illuminate scaling issues. The hybrid model incorporates algorithms whereby transport coefficients for use in fluid equations are derived using a kinetic simulation. The goal is to enable the fluid algorithms in the model to be able to more accurately represent low pressure operation. The consequences of power, pressure, and magnitude and orientation of applied magnetic fields were investigated. The authors found that the magnetic field configuration significantly affects the magnitude and distribution of fluxes incident on the substrate. A study of the Cu seed layer deposition process, carried out using a feature scale model, correlates changes in plasma properties with conformal deposition into trenches.

The use of hollow cathodes in deposition processes: A critical review

“… Compared to magnetron sputtering, a larger fraction of sputtered atoms is ionized; for magnetron sputtering M + /M  0.01 [78,346] and for sputtering with a hollow cathode M + /M  0.2 [250,259,260,269].…”

“…ACCEPTED MANUSCRIPT 75 discharge is confined by the extension tube and this increases the plasma density and therefore the sputtering efficiency [257,[259][260][261].…”

Investigation of the DSMC Approach for Ion∕neutral Species in Modeling Low Pressure Plasma Reactor

“…Modeling such devices is challenging due to their high plasma density, reactive environment, and low pressure [1,3]. The modular code, hybrid plasma equipment model (HPEM) [4], has been successfully applied to the numerical investigations of IMPVD [1,5,6,7]. However, as the development of plasma devices progresses towards the lower pressure regime (e.g., ≤ 5 mTorr), the breakdown of the continuum assumption limits the application of the fluid model in HPEM and suggests the incorporation of the kinetic method, such as the direct simulation Monte Carlo (DSMC), in plasma simulations.…”

“…Many steps from the semiconductor fabrication processes utilize the unique features provided by plasma. Currently low pressure, high plasma density reactors, such as the hollow cathode magnetron (HCM), are favored tools for the ionized metal physical vapor deposition (IMPVD) [1,2], a semiconductor plasma processing technology that is increasingly being applied to deposit Cu seed layers on semiconductor surfaces of trenches and vias with high aspect ratio (e.g. ≥ 5:1).…”

“…A large fraction of ionized atoms produced by the IMPVD process leads to an anisotropic deposition flux towards the substrate, a feature which is critical for attaining a void-free and uniform fill. Modeling such devices is challenging due to their high plasma density, reactive environment, and low pressure [1,3]. The modular code, hybrid plasma equipment model (HPEM) [4], has been successfully applied to the numerical investigations of IMPVD [1,5,6,7].…”