Boron ion source based on planar magnetron discharge in self-sputtering mode

Abstract

An ion source based on a planar magnetron sputtering device with thermally isolated target has been designed and demonstrated. For a boron sputtering target, high target temperature is required because boron has low electrical conductivity at room temperature, increasing with temperature. The target is well-insulated thermally and can be heated by an initial low-current, high-voltage discharge mode. A discharge power of 16 W was adequate to attain the required surface temperature (400 degrees C), followed by transition of the discharge to a high-current, low-voltage mode for which the magnetron enters a self-sputtering operational mode. Beam analysis was performed with a time-of-flight system; the maximum boron ion fraction in the beam is greater than 99%, and the mean boron ion fraction, time-integrated over the whole pulse length, is about 95%. We have plans to make the ion source steady state and test with a bending magnet. This kind of boron ion source could be competitive to conventional boron ion sources that utilize compounds such as BF(3), and could be useful for semiconductor industry application.

Short period La/B and LaN/B multilayer mirrors for ~68 nm wavelength

“…The boron rich compound B 4 C has been selected previously over boron because of its higher electrical conductivity [9] which simplifies deposition with commonly used DC magnetron sputtering techniques. Boron, being a semi-conductor at room temperature, is usually deposited by RF magnetron sputtering, but DC magnetron sputtering sources can be employed for boron when the target is heated above 400°C [10], where the conductivity improves sufficiently.…”

Boron-rich plasma by high power impulse magnetron sputtering of lanthanum hexaboride

“…LaB 6 was primarily selected for its very large fraction of boron, an element of many uses. Although it has been demonstrated that pure boron can be used in HiPIMS discharges, 15 working with pure boron targets is difficult. First, the electrical conductivity at room temperature is insufficient for HiPIMS unless a high target temperature of 600°C or higher is used.…”

Magnetron sputtering and electron beam evaporation systems for pure boron thin film coatings

“…The described equipment will be used to obtain pure boron coatings, promising for use in modern electronic devices and extreme ultra-violet optics, and boron nitride coatings with high hardness, which are in demand for surface hardening tasks in the industry. The considered methods for obtaining pure boron coatings using magnetron discharge [20] and forevacuum electron source [21] are original and first implemented by the authors of the article. The analog of the first method can be considered a highfrequency magnetron discharge with a dielectric target [19].…”

“…This article discusses the equipment for the implementation of two plasma methods developed by us for depositing thin films of pure boron to the surface. The first is the use of a magnetron with a heated target made of pure crystalline boron, in which its specific resistance decreases to a value at which the magnetron discharge can function normally [20]. The second is the use of a fore-vacuum source of electrons for heating a pure boron target and its evaporation.…”