Implementation of the IMEC-cleaning in advanced CMOS manufacturing

This paper is a review of the IMEC-cleaning. The fundamental physical and chemical principles for the basis of the IMEC-cleaning concept are described, which involves first of all, the removal of particles by breaking the van der Waals force by undercutting the particles and creating a repulsive zeta potential between the particle and the surface; secondly, removing the metal contamination from the surface using low pH mixtures; and finally, drying the surface after wet treatment with a Marangoni drying technique, which results in a very thin residual water layer. This IMEC-cleaning has been used in an IC (Integrated Circuit) prototype line and data over a period of 2 years are presented. The particle removal efficiency for several types of particles and surfaces is usually above 99%. The metal contamination is below 1. 1010 at.cm−2. The defect density of a gate oxide of 5.8 nm is well below 1 defect.cm−2 over several runs. And the cost of this IMEC-cleaning is lower than the more conventional cleaning techniques.

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