Area-selective atomic layer deposition of SiO2 and Ru for self-aligned fabrication
With top-down processing relying on photolithography and etching reaching its limits in terms of alignment accuracy, there is currently a need for implementation of bottom-up processing steps in semiconductor fabrication. Area-selective atomic layer deposition (ALD) aims at the deposition of material only on specific surfaces, and thereby enables self-aligned fabrication.
In this presentation, several methods for area-selective ALD will be described, and the challenges in this field will be discussed. Special attention will be given to two recently developed methods: (i) area-selective ALD of SiO2 relying on the use of inhibitors in ABC-type ALD cycles,1 (ii) area-selective ALD of Ru with improved selectivity by combining ALD with selective etching. The opportunities for using such area-selective ALD processes in self-aligned fabrication schemes will be discussed.
1. A. Mameli, M.J.M. Merkx, B. Karasulu, F. Roozeboom, W.M.M. Kessels, A.J.M. Mackus, ACS Nano 11, 9303 (2017)