Pd/Si plasma immersion ion implantation for selective electroless copper plating on SiO2

• Published in: Applied physics letters 1992-06, Vol.60 (22), p.2767-2769
• Main Authors: MENG-HSIUNG KIANG, LIEBERMAN, M, A, CHEUNG, N. W, QIAN, X. Y
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.106871

Selective deposition of copper in SiO2 trenches has been carried out using Pd/Si plasma immersion ion implantation and electroless Cu plating. To form the seed layer for electroless Cu plating on SiO2, sputtered Pd and Si atoms were partially ionized by the Ar plasma and then deposited at bottoms of SiO2 trenches; Ar ion beam was then applied to assist the mixing of the deposited Pd/Si films with the SiO2 substrate by recoil implantation. We found a threshold Pd dose of 2×1014/cm2 is required to initiate the electroless plating of Cu. By careful control of the anisotropic etching of the oxide trenches and proper choice of the Pd dose, 1-μm wide Cu filled lines with flat surfaces suitable for planarized multilevel metallization were successfully fabricated.