Presentation Information
[3G11]Subnanoscale analysis of adsorption structures of organic molecules for corrosion protection on Cu(111) surface investigated by in-liquid atomic force microscopy
*Kaito Hayashi1, Daiki Oka1, Kazuki Miyata1,2, Megumi Uno3, Chikako Takatoh3, Takeshi Fukuma1,2 (1. Division of Frontier Engineering, Kanazawa University, 2. Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, 3. EBARA Corporation)
The miniaturization of copper (Cu) interconnections is crucial to advancing semiconductor integration. During the manufacturing process, benzotriazole (BTA) is used to form the anticorrosive film on Cu surface. However, local corrosion still occurs. To understand its origin, we aim to image the BTA molecules on a Cu(111) substrate using frequency-modulation atomic force microscopy (FM-AFM) and three-dimensional scanning force microscopy (3D-SFM) in liquid. First, we electropolished a Cu(111) substrate, then immediately dropped a KCl solution onto it. Using this sample, we obtained FM-AFM images with atomic-resolution of Cl-terminated Cu(111) surfaces. Then, we slowly replaced the imaging solution with a dilute BTA solution. A transition from an atomic-scale periodic structure to a non-periodic, irregular structure was observed at the surface, indicating the formation of a BTA film. A 3D-SFM image shows the tilted stripe-shaped contrasts, suggesting BTA molecules or hydration layers.