Channel spark discharges for thin film technology

Short electrical discharges with high energy are a very promising tool for controlled ablation and deposition of materials. A source for pulsed discharges is the channel spark discharge. This channeled discharge can produce electron pulses of about 15 keV and 1 kA. Introducing the pulse energy in the target over a small area and a small penetration depth within a short time (100 ns), a very high energy density is produced in the surface region leading to very high instantaneous ablation rates. The energetic pulse parameters are comparable to the laser light pulses in PLD. Ablated material produced by the discharge is distinguished by its high degree of ionization and excitation. The development of the plasma has been characterized by the emitted optical radiation, spectrally resolved. Lines of ablated material and working gas (nitrogen) are observable in the emission spectrum. For reactive deposition of BN-films, for instance, the energy deposited in discharge gas may be used directly for the deposition process. Therefore, the channel spark discharge represents an effective and inexpensive source for highly excited and reactive deposition.