Atomic layer deposition of hafnium dioxide films using hafnium bis(2-butanolate)bis(1-methoxy-2-methyl-2-propanolate) and water

HfO2 films were grown by atomic layer deposition (ALD) from a mononuclear Hf(O'BU)(2)(OCMe2CH2OMe)(2) complex and H2O at temperatures in the range 275-400degreesC on borosilicate glass and Si(100) substrates. The growth of the densest films was achieved at temperatures above 300degreesC. The growth rate was influenced by the thermal decomposition of the Hf precursor. The as-deposited films were oxides with an O:Hf ratio of 2.0 +/- 0.2, although containing large amounts of impurities. Crystalline monoclinic films were grown at temperatures exceeding 325degreesC, whereas at lower temperatures the films mostly remained amorphous. On the whole, the refractive index of the films varied between 1.95 and 2.00. The effective permittivities of the dielectrics in Al/HfO2/p-Si(100) capacitor structures varied between 12 and 14, slightly increasing with growth temperature.