Morphology Behavior of Copper Films Deposited after Wet Surface Treatment on Polished Alumina

Alexander Flacker,Gabriela Gomes,Michele Silva,Ricardo Teixeira

doi:10.21577/0103-5053.20220017

Abstract

In this paper, a pre-treatment process for electroless copper (Cu) deposition on the polished alumina (Al2O3) 99.9% and the behavior of Cu plating by electroless process after Al2O3 surface treatment were explored. Our work was carried out by changing the roughness of Al2O3 through micro-etching (coarsening), nucleation its surface by a two-step method (sensitization and activation) and electroless Cu plating deposited using non-commercial solution having formaldehyde as reducer, alkaline pH and operating temperature of 30 ºC. Contact angle system (CA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), mechanical profilometer (DekTak XT) atomic force microscopy (AFM) and analysis by Gwyddion v2.27 software were used to evaluate the wet treatment and the morphology of the electroless deposition (ED) of Cu on the Al2O3 surface. The results show that the surface treatment of purity polished Al2O3 with 0.1% of vitreous materials present into the substrate surface, presents a high performance in ED film at low temperature (30 ºC), during the Cu deposition, obtaining more compact and uniform film, with small grain size, uniform thickness, and a high purity Cu metallic deposit.

Highlights

Electroless deposition (ED) of metals and alloys on non-metallic materials such as ceramics, carbon, plastics, polymers, semiconductors and dielectrics are increasing for a wide range of commercial applications.[1,2,3,4,5,6,7,8] The process is important in the printed circuit industry.[9]
To have a qualitative assessment of whether there was a change in the behavior on the Al2O3 surface after coarsening, surface wettability was evaluated by a contact angle
We proposed a surface treatment as lowcost alternative to other more expensive methods, such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma spraying or electrodeposition, to obtain a good adherence with metallic film

Summary

Introduction

Electroless deposition (ED) of metals and alloys on non-metallic materials such as ceramics, carbon, plastics, polymers, semiconductors and dielectrics are increasing for a wide range of commercial applications.[1,2,3,4,5,6,7,8] The process is important in the printed circuit industry.[9]. The morphology and roughness of the electroless Cu deposition system performed on the alumina coarsened was studied combining atomic force microscopy (AFM), mechanical profilometer (DekTak XT) and scanning electron microscope (SEM).

Results

Conclusion