A Clean Method for Making of Nano-Wires
Publication Date: 2010-Aug-05
The IP.com Prior Art Database
Disclosed is invention for a two-phase cleaning solution containing a water-HF solution, and a second phase chemistry.
A Clean Method for Making of Nano -Wires
In order to maintain the RC performance of back-end-of-line (BEOL), integration of
ultra-low-k material (dielectric constant < 2.4) is needed for 22nm and beyond. However, due to the modulus of the ULK and the very tight pitch (<100 nm), dielectric
flop-over is an issue for process development. Further investigation found that the
dielectric flop-over comes after diluted HF clean process. Inventors also observed that
the degree of flop-over depends on rinse/dry chemistry. Three factors relate to the
observed patterned dielectric defection:
• Capillary force from/during dHF clean
• Geometry of the patterned dielectric
• Material property- Modulus
This is more serious for the trench first with metal hard mask (TFmHM) process due to
the high stress of the TiN hard mask.
Since the patterned dielectric flop-over has been observed post dHF, this disclosure
resolves the problem by reducing the capillary force. A new approach must resolve the
issue and fulfill the following three topics:
• Providing a method to fabricate ULK damascene without pattern flop-over
• Optimization of a clean process/ chemistry to reduce capillary force
• Reducing defectivity and enhancing high-volume manufacturability
The invention is a two-phase cleaning solution containing a water-HF solution, and a
second phase chemistry.
This chemistry needs to fulfill the following conditions:
• Solubility of Chemistry A to wafer is low
• DensityA < Densit...