Prevention of Cu degradation using in situ N2 plasma treatment in a dual-damascene process

Abstract

Articles you may be interested inOn the pressure effect in energetic deposition of Cu thin films by modulated pulsed power magnetron sputtering: A global plasma model and experimentsThe surface state of copper after an etching process using CF 4 gas has been analyzed. Copper surface stability against corrosion is evaluated through a storage test performed under high-humidity conditions after the etching process. The storage test reveals that the copper surface suffered from both corrosion and oxidation. The copper degradation is caused by a postreaction between moisture and residual fluorine, wherein the resulting oxygen-containing copper film features a rough surface morphology. We examined in situ plasma treatments with several gases to reduce corrosive reactions. Results indicate that in situ N 2 plasma treatment removes fluorine residue from the copper surface, and that this treatment effectively stabilizes the copper surface against corrosive conditions.

Characterization of Information-Transmitting Materials Produced in Ionic Liquid-based Neuromorphic Electrochemical Devices for Physical Reservoir Computing

“…This discrepancy may be attributed to the instability of CuF 2 and fluorocarbon (CF x ) on metallic Cu. Previous studies on the dry etching process of Cu using CF 4 gas have shown that CuF 2 and CF x on Cu are highly unstable and decompose to Cu 2 O in a high humidity (80%) atmosphere . The electrochemical reactions at the Cu-IL/Pt interface in the present IL-PRD are strongly influenced by H 2 O, as mentioned earlier.…”

Comparison of H2and NH3Treatments for Copper Interconnects

“…Increasing the treatment time to 30 s improves the adhesion. Moreover, the tested sample with 30 s NH 3 treatment had a higher adhesion strength than the H 2 -treated sample because the former treatment forms Cu-N chemical bonds [14,15]. The adhesion strength between the Cu film and the barrier layer in H 2 -treated samples did not vary significantly with the treatment time.…”

Control of oxidation on NiSix during etching and ashing processes

“…The N 2 plasma treatment achieves a defluorination effect on NiSi x after the etching process. These phenomena are thought to be equal with the phenomena of our previous report at the copper surface [10]. Likewise, it is thought that the nitrogen ions play a role to sputter the fluorine residues and the fluorine residues are removed as volatile matter after the reaction with nitrogen.…”