THE EFFECT OF RAPID THERMAL ANNEALING ON STRUCTURAL AND ELECTRICAL-PROPERTIES OF TIB2 THIN-FILMS

This work reports on the effect of post-deposition rapid thermal annea ling on the structural and electrical properties of deposited TiB2 thi n films. The TiB2 thin films, thicknesses from 9 to 450 nm, were depos ited by e-beam evaporation on high resistivity and thermally oxidized silicon wafers. The resistivity of as-deposited films varied from 1820 mu Omega cm for the thinnest film to 267 mu Omega cm for thicknesses greater than 100 nm. In the thickness range from 100 to 450 nm, the re sistivity of TiB2 films has a constant value of 267 mu Omega cm. A rap id thermal annealing (RTA) technique has been used to reduce the resis tivity of deposited films. During vacuum annealing at 7 x 10(-3) Pa, t he film resistivity decreases from 267 mu Omega cm at 200 degrees C to 16 mu Omega cm at 1200 degrees C. Heating cycles during RTA were a se quence of 10 s. According to scanning tunneling microscopy analysis, t he decrease in resistivity may be attributed to a grain growth through polycrystalline recrystallization, as well as to an increase in film density. The grain size and mean surface roughness of annealed films i ncrease with annealing temperature. At the same time, the conductivity of the annealed samples increases linearly with grain size. The obtai ned results show that RTA technique has a great potential for low resi stivity TiB, formation. (C) 1997 Published by Elsevier Science S.A.