atomic layer deposition Inductively coupled plasma (ICP) sources were developed for use in the semiconductor industry decades ago, at a time when mainly silicon oxide and silicon nitride were being deposited by plasma sources. Today new materials have more exacting demands, especially for plasma-assisted atomic layer deposition. The older sources have problems with oxygen contamination from sputtered dielectric windows (typically quartz or alumina). However, apart from that, the idea of using a high-density power source generated in a small area tube and then diluting the activated species over a larger deposition area may be an idea that’s had its day. Small area sources are used so that the backflow of metalorganic into the dielectric tube is minimized since such deposition can block RF transmission to the plasma gas, and potentially cause damage to the dielectric liner.
Enter OkyayTech Layerava® for the rescue, free of oxygen contamination problems and able to cope with both metallic and insulating deposition on the cathode. Now a high-density plasma source can be made to the same dimensions as a substrate – there is no need to dilute the plasma species over a larger area. The plasma source can also be brought closer in. The tool utilizes a large area of high-density hollow cathode source and a compact reactor design. Below is a useful table showing some results from the University of Connecticut. These demonstrate the advantage of breaking away from the old ICP plasma delivery paradigm. OkyayTech Layerava has it’s own sample entry port, and ellipsometer ports. Additionally, the new large-area source is capable of a very high electron density of 1e13 cm-3 over the full deposition area.