Characterization of Atomic Layer deposited (ALD) Al2O3 and ZnO films for Nano and Micro Applications
R. Kotha, A.A. Ayon
MEMS Research Lab, University of Texas San Antonio, US
Keywords: atomic layer deposition (ALD), oxides, stress, surface roughness
Abstract:Atomic layer deposition (ALD) is an emerging thin film deposition technique that has created a great potential to enhance device performances in the field of micro and nanotechnology. ALD films are known for their excellent conformality, uniformity and their accurate thickness control in the nanoscale regime, and can be used in deposition of high k-dielectrics, metallization, nucleation layers and barrier materials. In this research, characterization of ALD Aluminum Oxide (Al2O3) and Zinc Oxide (ZnO) thin films has been carried out. ALD films of two different thicknesses of each type were deposited at a lower temperature of 100C on polished <100> silicon wafers. The precursors employed for Al2O3 are Trimethylaluminum (Al(CH3)3, TMA) and water, and for ZnO are Diethylzinc ((Zn(CH2CH3)2, DEZ) and water. Various parameters such as film thickness, stress and surface roughness have been measured for as deposited films. Thermal treatment of ALD films was carried out upto to 400C in steps of 100C and the above parameters are measured. Scanning electron microscope (SEM) images of thermally treated films at 400C were taken and the film’s microstructure properties were studied.