Mthod for the surface treatment of semiconductors by particle bombardment

DETAILED DESCRIPTION I claim: 1.
A method for the extraction of a plasma beam from a low-pressure plasma, comprising the steps of generating a low-pressure plasma by electric and magnetic fields, applying a radio frequency voltage between an extraction electrode which comprises a fine grid and a second electrode, maintaining the plasma between the extraction and second electrodes with an attendant generation of ion accelerating d.
c.
voltage between the plasma and the extraction electrode whereby the plasma is positively self-biasing against the extraction electrode and the extracted steadily flowing ion current is superimposed with an electron current of the same magnitude pulsating synchronously with the applied radio frequency to compensate for the ion current, controlling the magnitude of the d.
c.
voltage and hence the beam energy by the amplitude of the radio frequency voltage between the plasma and the extraction electrode, with and shaping the low-pressure plasma and the extracted plasma beam by d.
c.
magnetic fields of suitable magnitude and configuration.




Description:
The invention relates to a method for the removal and structuring of the surfaces of solids, as well as the production of surface doping, by particle bombardment.
In addition, a process for the extraction of a plasma beam from a low-pressure plasma, and a device for performing the same, are presented.
The bombardment of the surfaces of solids with beams of atoms or molecules over as large an area as possible is an important process for modern surface and thin film technology.
The range of particle energies between several hundred electron volts and several kiloelectron volts is of particular importance here because, in this case, the interactive processes taking place remain limited from a few to a few tens of atomic surface layers.
The applications of such sources of particle beams can generally be divided into two groups: 1.
Atoms and molecules of the respective material are released from the surface of the bombarded solid by the particle bombardment (solid atomization by ion bombardment or "sputtering")