RF bias is typically employed for an in-situ cleaning of the sample prior to the main deposition. The cleaning process is carried out by a plasma created in the vicinity of the sample when the chamber is filled with gas and a RF power is applied to the stage.
The surface of the sample in contact with plasma will be bombarded by ions, activated species, excited species, and thermal species. Ions and excited species will release their energies of ionization or excitation when they impinge on the surface of the sample. Locally this release of energy will generate a high local temperature, which will result in a removal of the impurities from the surface of the sample.
As standard Mantis sample stages come with RF bias feedthrough integrated into the assembly. For enabling the RF sample cleaning feature, it is necessary to add 300W RF power supply and have a Ar gas supply.
A DC bias applied to the growing sample influences the total energy and momentum flux of all charged species arriving at the substrate, and hence plays a significant role in modifying the structure of the growing film.
The ions approaching the sample acquire additional energy from the electric field created by the DC bias. The ion bombardment with increased energy results in filling of the voids and the densification of the columnar structure of the growing film. In addition, the energy transferred to the surface increases the surface adatom mobility, which consequently, affects the density of film structure.
During deposition of nanoparticles, the amount of applied DC bias significantly influences the porosity of the nanoparticle film, which in turn affects its resulting physical, optical and electrical characteristics.
The DC bias feature is enabled by adding a DC power supply to the configuration. Typically for sputtering applications, we supply DC power supplies with voltage up to 600V and for nanoparticle control we offer 6kV power supply.
Linear Z-shift motion ensures that the source to sample distance can be changed. This feature is useful for determining the optimum deposition conditions for a particular application. Current design of the sample stage allows Z-shift motion in the range of 0-100mm.
Manual and Motor-driven Shutters
The sample stage can be outfitted with an integrated shutter. The rotary shutter is configured with a magnetically coupled rotary feedthrough that ensures longevity and UHV compatibility. The stage can be outfitted with either manual or motor actuated shutter.