Characterization of Post Etch Residues Depending on Resist Removal Processes after Aluminum Etch

The subject of this report is the characterization of plasma etch residues after a metal etch process with Cl2/BCl3 etch gases. One of the interactive factors in the removability of the residues is the photo-mask removal process (DSQ). Depending on the DSQ process the molecular structure of the residues will differ. For our findings, we used laser spectroscopy and Fourier-transformed infrared spectroscopy to obtain information about the degree of the cross-linking of the molecular structure of residues in a post-metal etch cleaning process. The post-etch cleaning is important for removing residues remaining after the metal structuring process. The main goal is to use emission spectroscopy for studying the compounds of the dry-etch related residues. Finally, it was shown that small variations in wafer treatment directly after dry-etching results in different solubilities of residues in HDA (hydroxylamine) based solutions. [1]