SYNTHESIS OF ZRO2 AND Y2O3-DOPED ZRO2 THIN-FILMS USING SELF-ASSEMBLEDMONOLAYERS

Undoped or Y2O3-doped ZrO2 thin films were deposited on self-assembled monolayers (SAMs) with either sulfonate or methyl terminal functional ities on single-crystal silicon substrates, The undoped films were for med by enhanced hydrolysis of zirconium sulfate (Zr(SO4). 4H(4)O) solu tions in the presence of HCl at 70 degrees C, Typically, these films w ere a mixture of two phases: nanocrystalline tetragonal- (t-) ZrO2 and an amorphous basic zirconium sulfate. However, films with little or n o amorphous material could be produced, The mechanism of film formatio n and the growth kinetics have been explained through a coagulation mo del involving homogeneous nucleation, particle adhesion, and aggregati on onto the substrate, Annealing of these films at 500 degrees C led t o complete crystallization to t-ZrO2. Amorphous Y2O3-containing ZrO2 f ilms were prepared from a precursor solution containing zirconium sulf ate, yttrium sulfate (Y-2(SO4)(3) . 8H(2)O), and urea (NH2CONH2) at pH 2.2-3.0 at 80 degrees C, These films also were fully crystalline afte r annealing at 500 degrees C.