Impact of Chamber Pressure on Sputtered Particle Energy

Impact of Chamber Pressure on Sputtered Particle Energy

Wilmert De Bosscher
Soleras Advanced Coatings

Depending on the specific market application of thin film coatings on a rigid or flexible substrate, it is often essential controlling the energy of the sputtered particles arriving on the substrate. It may help defining the layer density/porosity, stress in the layer or heat load transferred to the substrate. An easy parameter we have in hand and significantly impacting the particle energy is the process pressure in the sputter chamber or compartment. For this study, results from experimental work and modelling will be combined for understanding the impact of sputtering over a wide pressure range on process parameters (e.g. target I-V behaviour) and on layer properties (e.g. optical and electrical performance). We found correlations between real measurements and comparable Monte Carlo simulation results; allowing for defining some general trends that could be summarized in an analytical approximation formula. The analytical approach opens new opportunities for easy approximation of particle energies arriving at the substrate for any change in coater geometry, pressure, temperature and used species (gas and target material).