SURFACE AND INTERFACE STUDY OF TITANIUM NITRIDE ON SI SUBSTRATE PRODUCED BY DYNAMIC ION-BEAM MIXING METHOD

Crystal growth of TiN on Si substrate under dynamic ion beam mixing (DIBM) processing was monitored by reflection high-energy electron diffraction (RHEED) and the interface was studied by transmission electron microscope (TEM). The TEM observation has revealed that the intermixed layer between the Si substrate and TiN film is composed of three different types of sublayers. The thicknesses of the first and the second sublayers were same as approximately 7-8 nm and approximately 3-4 nm, respectively, independent of different arrival ratios of Ti/N. The thickness of the third layer, however, was approximately 6 nm for the arrival ratio of nearly unity whereas it was approximately 14 nm for the arrival ratio greater than unity. Characterization of these sublayers with a field-emission analytical electron microscope (AEM) has revealed that these three sublayers are of an amorphous structure, composed of a mixture of Si and N, of a mixture of Si, N and small amount of recoil-implanted Ti, and of a mixture of Si, N, and Ti, for the 1st, 2nd and 3rd sublayers, respectively. TiN (001) is epitaxially grown on Si (001) along the incident direction of nitrogen ions even though the intermixed layer exists inbetween the TiN film and Si substrate.