Topographically selective deposition

In this paper, we present a topographically Selective Deposition process which allows the vertical only coating of three-dimensional (3D) nano-structures. This process is based on the alternate use of plasma enhanced atomic layer deposition (PEALD) and sputtering carried out in a PEALD reactor equipped with a radio-frequency substrate biasing kit. A so-called super-cycle has been conceived, which consists of 100 standard deposition cycles followed by an anisotropic argon sputtering induced by the application of a 13.56 MHz biasing waveform to the substrate holder in the PEALD chamber. This sputtering step removes the deposited material on horizontal surfaces only, and the sequential deposition/etch process allows effective deposition on vertical surfaces only. Thus, it opens up a route for topographically selective deposition, which can be of interest for the fabrication of 3D vertical Metal-Insulator-Metal devices.