Dc planar magnetron sputter deposition of boron thin films and their properties

In this study, boron thin films were deposited on metal substrates using planar direct current (DC) magnetron sputtering with a pure boron target. Boron has high electrical resistance, severely impeding its application in a magnetron discharge; however, it is a semiconductor and its resistance decreases as the temperature increases. We used a planar magnetron with a boron target that was heated in a DC discharge current up to 50 mA in argon and nitrogen at a pressure of 2-3 mTorr. For these discharge parameters, at a distance of 5 cm from the target the boron deposition rate was about 150 nm/h. Thin boron films with thickness up to 1 μm were obtained and their surface morphology was studied. The deposition technique and the properties of the films are discussed.