Physics and phenomena in pulsed magnetrons: an overview

Abstract

This paper reviews the contribution made to the observation and understanding of the basic physical processes occurring in an important type of magnetized low-pressure plasma discharge, the pulsed magnetron.In industry, these plasma sources are operated typically in reactive mode where a cathode is sputtered in the presence of both chemically reactive and noble gases typically with the power modulated in the mid-frequency (5–350 kHz) range. In this review, we concentrate mostly, however, on physics-based studies carried out on magnetron systems operated in argon. This simplifies the physical–chemical processes occurring and makes interpretation of the observations somewhat easier.Since their first recorded use in 1993 there have been more than 300 peer-reviewed paper publications concerned with pulsed magnetrons, dealing wholly or in part with fundamental observations and basic studies. The fundamentals of these plasmas and the relationship between the plasma parameters and thin film quality regularly have whole sessions at international conferences devoted to them; however, since many different types of magnetron geometries have been used worldwide with different operating parameters the important results are often difficult to tease out. For example, we find the detailed observations of the plasma parameter (particle density and temperature) evolution from experiment to experiment are at best difficult to compare and at worst contradictory.We review in turn five major areas of studies which are addressed in the literature and try to draw out the major results. These areas are: fast electron generation, bulk plasma heating, short and long-term plasma parameter rise and decay rates, plasma potential modulation and transient phenomena. The influence of these phenomena on the ion energy and ion energy flux at the substrate is discussed. This review, although not exhaustive, will serve as a useful guide for more in-depth investigations using the referenced literature and also hopefully as an inspiration for future studies.

Perspectives on oblique angle deposition of thin films: From fundamentals to devices

“…There are many excellent reviews dealing with the first two issues when working under a normal configuration [298,299], but the third has only been scarcely addressed, even under simplified conditions. In this section, we will focus on some of the mechanistic aspects that are important to account for the MS-OAD of thin films in connection with the development of a columnar nanostructure.…”

Hard Nanocomposite Coatings

“…At present, the following four methods make it possible to deposit oxide coatings with a very high deposition rate, and they are the subject of intensive development: (1) gas flow sputtering (159)(160)(161)(162)(163)(164)(165)(166), (2) high-power pulsed magnetron sputtering (HPPMS) (167)(168)(169)(170)(171)(172)(173), (3) ionized evaporation (174)(175)(176)(177)(178)(179)(180)(181)(182)(183), and (4) magnetron sputtering from a molten target (184)(185)(186)(187)(188)(189)(190)(191)(192)(193). The principles of these methods are schematically shown in Figure 31.…”

Pulsed electron beam propagation in argon and nitrogen gas mixture

“…The choice of gas compositions was explained by their wide application in technological processes of the most industrial technologies. 32,33 …”