Effects of NH3 plasma pretreatment on initial reactions of atomic layer deposition TaN barrier layer on SiOC dielectric

Abstract

Initial reaction mechanisms of atomic layer deposition TaN barrier layer on the different group-terminated SiOC surfaces have been investigated by density functional theory. TaCl5 molecules are hardly absorbed on –CH3 terminated surfaces mostly existing in SiOC dielectrics, which retards a uniform TaN layer growth. After NH3 plasma pretreatment, –NH2 terminated surfaces enhance the chemisorptions of TaCl5 and guarantee ALD TaN reaction sequences to go ahead, thus a uniform TaN barrier layer on SiOC dielectrics can be easily synthesized. In addition, HCl molecules as by-products are easily desorbed to benefit a high quality TaN layer with low Cl contaminations.