Design and optimization of ferric chloride and oxalic acid based slurry to chemically mechanically polish stainless steel

Abstract

To enhance the chemical mechanical polishing (CMP) efficiency of flexible display substrates, a polishing slurry based on ferric chloride and oxalic acid was proposed for polishing 304 stainless steel substrates. An orthogonal optimization test was designed to determine the significance order of the influence of abrasive size, abrasive content, oxalic acid content and ferric chloride content on the material removal rate (MRR) and surface roughness (surface arithmetical mean height of area, Sa). The aim was to investigate the effects of ferric chloride and oxalic acid on MRR. An optimized polishing slurry capable of achieving an MRR of over 560 nm/min and a Sa as low as 8 nm after 30 min was obtain. Compared with the conventional polishing slurry, whose MRR is 226.56 nm/min, the novel slurry has doubled its polishing efficiency or more.

Keywords

• chemical-mechanical planarization
• 304 stainless steel
• ferric chloride-oxalic acid
• material removal rate
• surface roughness