Darina Manova
Formation of Aluminium Nitride by Plasma Immersion Ion Implantation
Supervisor: Prof. Dr. Rauschenbach [Experimental physics IV]
Date of oral examination: 07/06/2001
108 pages, english
AlN is a material with a large potential for current and future industrial applications in two different areas: protective wear resistant coatings for tribological applications and thin films for optoelectronic and microelectronic devices. Plasma immersion ion implantation (PIII) is a relatively new method for surface modification of materials, where the sample is immersed in a plasma, and ion implantation occurs by applying high voltage pulses to it. In a modification of this technique, metal plasma immersion ion implantation and deposition (MePIIID), both aluminium and nitrogen ions are implanted to form AlN layers on arbitrary substrates at low temperatures. In this work a detailed investigation of nitrogen PIII into Al was performed, starting with basic PIII investigations with a special focus on the relation of temperature, high voltage, frequency and dose rate. Additionally, homogeneity investigations were done for MePIIID. A systematic study of the mechanism of nitrogen diffusion in aluminium over a broad temperature range and the dependence of the diffusion on the preparation method and oxygen impurities was made for PIII. The formation of AlN by MePIIID, with applying up to 10 kV was examined with respect to the possibilities and restrictions of MePIIID as a deposition method for this compound. The structural, optical and mechanical properties of AlN films were investigated and compared with those of Al2O3, obtained by the same method.