Atomic Layer Deposition of Copper, Copper(I) Oxide and Copper(I) Nitride on Oxide Substrates

• Main Author: Törndahl, Tobias
• Format: Doctoral Thesis
• Language: English
• Published: Uppsala universitet, Institutionen för materialkemi 2004
• Subjects: Inorganic chemistry; Atomic Layer Deposition; ALD; copper; copper(I) oxide; copper(I) nitride; deposition pathway; CuCl; Cu(hfac)2; oxide substrates; epitaxy; DFT; ab-initio; Oorganisk kemi
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4651; http://nbn-resolving.de/urn:isbn:91-554-6081-X

Thin films play an important role in science and technology today. By combining different materials, properties for specific applications can be optimised. In this thesis growth of copper, copper(I) oxide and copper(I) nitride on two different substrates, amorphous SiO2 and single crystalline α-Al2O3 by the so called Atomic Layer Deposition (ALD) techniques has been studied. This technique allows precise control of the growth process at monolayer level on solid substrates. Other characteristic features of ALD are that it produces films with excellent step coverage and good uniformity even as extremely thin films on complicated shaped substrates. Alternative deposition schemes were developed for the materials of interest. It was demonstrated that use of intermediate water pulses affected the deposition pathways considerably. By adding water, the films are thought to grow via formation of an oxide over-layer instead of through a direct reaction between the precursors as in the case without water. For growth of copper(I) nitride from Cu(hfac)2 and ammonia no film growth occurred without adding water to the growth process. The Cu3N films could be transformed into conducting copper films by post annealing. In copper growth from CuCl and H2 the water affected film growth on the alumina substrates considerably more than on the fused silica substrates. The existence of surface -OH and/or -NHx groups was often found to play an important role, according to both theoretical calculations and experimental results.