Deposition of epitaxial Si/Si-Ge/Ge and novel high-K gate dielectrics using remote plasma chemical vapor deposition

Abstract

Both high quality epitaxial Si/Si-Ge/Ge films and novel high-k gate dieletrics have been deposited using an upgraded Remote Plasma Chemical Vapor Deposition (RPCVD) system. The upgrade of the RPCVD system consisted of two parts. The first part involved design and installation of a high-density inductively coupled plasma (ICP) source with its peripheral units, in place of an old surface analysis chamber. As a new deposition chamber, this chamber is capable of generating high plasma density with significantly lower ion energy. The second part involved modification of an existing deposition chamber for high-k film deposition. With the final integration of the new RPCVD system, better interfacial quality, lower thermal budget, less contamination and autodoping, and easier process control are expected. Experiments on epitaxial Si growth were conducted in the new RPCVD chamber in order to characterize growth dependence on different processing parameters. The process was extended to epitaxial Ge/SiGe films on Si that are beyond their Critical Layer Thickness (CLT). High quality epitaxial Si1-xGex (x>0.5) and Ge metastable films were achieved with epitaxial thicknesses at least 5 times higher than the corresponding CLT. High-k gate dielectric growth was performed in another modified deposition chamber. Low temperature RPCVD HfO2 was obtained with excellent physical and electrical characteristics. Finally, epitaxial Ge/SiGe and novel high-k dielectrics processes were integrated to fabricate MOS capacitors. These capacitors, with excellent structural and electrical properties, significantly increased the potential to fabricate high channel mobility MOSFET devices using RPCVD.