Dry Etching of Polyimide in  O 2 ‐  CF 4 and  O 2 ‐  SF 6 Plasmas

Abstract

The plasma etching of the type H Kapton polyimide film has been studied in a parallel plate reactor with two different gas mixtures; O~-CF4 and Of-SF~. High etching rate (0.5-3 ~m/min) has been obtained in both cases. At a pressure of 0.2 Torr an anomalous loading effect is observed which is attributed to the nitrogen released by the polyimide. The gaseous effluents from etching have been detected by mass spectrometry and indicate that both atomic oxygen and atomic fluorine are the main etchants of the polymer. A comparison with silicon etching in a SF6-O2 plasma is made in order to give the main channels of the reaction scheme. XPS measurements of the polyimide surface before and after etching are consistent with the mass spectrometric observations.

Plasma etching of As2S3 films for optical waveguides

“…On the other hand PR etch rate was the highest when $80% of oxygen was added to CF 4 , which coincides with previous literature [14]. Oxygen radicals are the main polymer (PR) etchant.…”

Residue-free plasma etching of polyimide coatings for small pitch vias with improved step coverage

“…[14][15][16][17] Atomic oxygen is the main etchant of polyimide by abstraction and/or addition of oxygen atoms to unsaturated groups. 1 It is important to note that atomic oxygen is not capable of attacking undamaged structures.…”

“…Ion bombardments and/or natural defects are necessary in order to open the benzene rings and allow etching. Addition of atomic fluorine in the plasma chemistry has been proven to enhance the production of atomic oxygen, 14 thereby increasing the etching efficiency. In addition, atomic fluorine also reacts in two different ways with the PI surface to increase the etch rate.…”

Characterization of aluminium nitride and aluminium oxide thin films sputter-deposited on organic substrates

“…This finding supports the assumption that the activated oxygen which is added to the plasma for reactive Al 2 O 3 deposition or which is released from the Al 2 O 3 target in the RF sputtering mode plays a crucial role. This is especially true when knowing that plasmas containing oxygen are typical atmospheres for dry-patterning organic materials (Turban and Rapeaux 1983;Bagolini et al 2002;Buder et al 2006). …”