Patent ID: 9447493
Filing Date: 2016-09-20
CPC Classification: B22F,C23C,H01J

Claim Text:
1. A plasma sputtering process for producing particles having a size of about 1 nm to about 10 μm by growth to said size of the particles through pick-up of sputtered target atoms on the surface of grains, the grains constituting previously formed particles or particle nuclei, the process comprising providing a target in a plasma generating apparatus, said apparatus having a characteristic length L introducing a process gas into said plasma generating apparatus and controlling the pressure inside the plasma generating apparatus in order to obtain a process gas number density n creating a plasma inside said plasma generating apparatus and controlling the energy provided to said plasma in order to obtain a plasma electron number density n sputtering atoms from said target by means of said plasma, allowing the sputtered atoms to be picked-up on the surface of the grains, the grains being present in the plasma, thus producing the particles having a size of about 1 nm to about 10 μm, and collecting the produced particles, wherein the plasma electron number density n wherein the following criterion is fulfilled L where L wherein the plasma generating apparatus is operated by a pulsed electric power supply with a frequency of at least 100 Hz and with a duration of the pulses of at least 5 microseconds, and wherein the energy provided to the plasma is sufficient to obtain ionization of at least 20 % of the sputtered atoms in said plasma.