Chemical Identification of Sub-20 nm Defects and Sub-Monolayer Residues with Nano IR PiFM

Abstract

With the advent of EUV lithography and other emerging processes such as area selective deposition, and SOIC hybrid bonding, the need to identify the chemical composition of defects is of paramount importance. The defects of concern range from 10nm to 500nm in lateral size and as thin as ~ 1 nm in thickness, which the current batch of molecular analytical tools cannot address adequately since the indications are that many of the defects and residues detected are organic in nature. In this paper, a relatively new nanoscale technique called infrared photo-induced force microscopy (IR PiFM), which combines non-contact atomic force microscopy (AFM) and infrared (IR) spectroscopy with ~ 5 nm spatial resolution, is introduced. The paper will show how the nanoscale hyperspectral IR PiFM data can provide unambiguous and speedy feedback to process engineers engaged in EUV lithography and other advanced semiconductor processes.