Wire-arc spray directed energy deposition: Correlation of chamber kits refurbishing and particle defects reduction in Ta/TaN thin-film physical deposition processes

Abstract

Physical Vapor Deposition (PVD) of Tantalum/Tantalum Nitride (Ta/TaN) liner and barrier plays a crucial role in the copper-interconnecting part of semiconductor manufacturing, and this is used for the 130 nm–5nm technology node and beyond. This study focuses on the surface preparation and characterization of wire-arc spray directed energy deposition (DED) coating in the refurbishment process of PVD chamber kits. Spray coating adhesion strength is enhanced due to the pretreatment of the substrate with grit blasting, which creates a suitable surface texture, and the replacement of aluminum alloy as wire-arc spray DED coating material from pure aluminum (99.8%). However, it was experimentally found that using high adhesion strength coating chamber kits increases the probability of out-of-control (OOC) occurrences in the mid-stage of the kit lifetime, and the fundamental reasons may be attributed to the spiky surface morphology of wire-arc spray DED coating layers. Finite element analysis simulates stress distribution and identifies stress concentration regions within the multilayer Ta/TaN thin film using two surface morphologies with significantly different curvature radii of spray coatings. Differences in wire-arc spray DED processing parameters include a slower travel speed, a longer spray time, and a lower feed rate. It is numerically simulated and experimentally observed that coating surface morphology dramatically affects thin film delamination, which is the primary cause of particle defects. This study emphasizes the potential mechanisms for forming particle defects, improved uniformity in spray coatings, and increased surface curvature radius to minimize stress concentration.

Keywords

• Semiconductor manufacturing
• Ta/TaN
• Wire-arc spray DED
• Finite element analysis
• Film delamination