Atomic layer growth of Pt films using dimethyl(N,N-dimethyl-3-butene-1-amine-N)platinum and O3

Abstract

Ultrathin Pt films have attracted interest for use in advanced microelectronics. However, the reaction chemistry between Pt precursors and reactants for atomic layer deposition (ALD) remains underexplored. Herein, we examine the ALD process of Pt films using dimethyl(N,N-dimethyl-3-butene-1-amine-N)platinum (DDAP) precursor and O-3. Despite the absence of self-limiting growth behavior, this method demonstrates high growth per cycle and produces high-quality films across a broad temperature range of 180-280 degrees C. The Pt films exhibited extremely low impurity levels, including carbon, nitrogen, hydrogen, and oxygen, as confirmed by secondary-ion mass spectrometry; this resulted in a low bulk resistivity of approximately 11 mu Omega<middle dot>cm, close to the theoretical value of Pt. The nucleation behavior strongly depended on the substrate and temperature. Higher temperatures reduced the incubation cycle and film roughness, particularly on Al2O3 substrates, facilitating more favorable nucleation compared to SiO2 because of its higher surface energy. Consequently, the minimum thickness required for continuous film formation decreased from similar to 5 nm for SiO2 to similar to 3 nm for Al2O3. These improvements also delayed the onset of the thickness-dependent resistivity increase in Al2O3. Our findings highlight the potential of the DDAP-O-3 process to fabricate ultrathin, continuous Pt films suitable for next-generation microelectronic applications that demand nanoscale metal layers.