FORMATION OF TIN TI ADHESION LAYERS BY COLLIMATED SPUTTERING/

Formation of a TiN/Ti adhesion layer by collimated sputtering for a st ructured surface with a high aspect ratio was investigated. The bottom coverage was simulated and the simulated and experimental results wer e compared. As a result, it was found that the simulated and experimen tal results were in agreement if the scattering of sputtered particles by gas was small. Three-dimensional simulation of wall coverage predi cted a formation of constriction at the top of the contact hole and th e formation of constriction was confirmed experimentally. The formatio n of constriction caused the peeling of an adhesion layer when a chemi cal vapor deposition (CVD) tungsten film was deposited. To avoid the f ormation of constriction, a tapered contact hole was used. It was foun d also that the contact resistance and junction leakage characteristic s were improved by collimation sputtering when an adhesion layer was d eposited in the contact holes with a high aspect ratio. It was conclud ed that this technology is advantageous in contact formation in device s with submicron structures.