Seed Repair by Electrodeposition in Pyrophosphate Solution for Acid Cu Superfilling

Abstract

Seed layer repairing, a complementary technology to the fabrication of continuous Cu seed layers for acid Cu superfilling, was carried out in alkaline pyrophosphate solution by modified two-step electrodeposition. A short potential pulse was applied for nucleation prior to the second step, which was application of a lower potential for growth. This technique increased the surface coverage of damaged Cu seed layers from 78.10% to 99.46%. It was also shown to have the ability to repair an artificially damaged Cu seed layer with a 55 nm wide trench and to guarantee successful filling performance.