Plasma Enhanced Atomic Layer Deposition

Cold plasmas are often used in chemical or physical deposition processes. In a chemical deposition process, they enable the process temperature to be lowered. With the advent of the ALD (Atomic Layer Deposition – ) process, it was obvious that manufacturers and researchers would also try to use cold plasmas. But unlike a PECVD (Plasma Enhanced Chemical Vapor Deposition) process, plasma is not used to dissociate a gaseous precursor. Plasma is only used in the oxidizing or reducing stage to bring reactive species such as O or H to the surface. This means that a particular design of plasma reactor is often required to limit ionic flux to the surface. The benefits and impact of plasma assistance on thin films deposited by PEALD are numerous. This assistance can be used to modify (increase) the growth rate per cycle, densify a material, modify its electrical resistivity, alter its crystalline nature, etc. All these advantages are presented and discussed in this section. All these advantages are presented and discussed in this article.

PEALD processes are mainly used in the microelectronics industry, and more generally in all nanotechnology-related activities using vacuum processes. The advent of space-based ALD processes, such as Roll to Roll and atmospheric ALD, offers a formidable challenge for the years to come, with the development of atmospheric plasma reactors to assist ALD and thus dispense with vacuum technology. It also remains to demonstrate the effectiveness of ALD processes for conformal deposition in patterns with aspect factors in excess of 100 for oxides or 50 for metals.