Analysis of the sidewall films formed during Si trench etching with photoresist mask in Cl rHBr-based plasma

The sidewall passivation films produced during Si trench etching with photoresist masks were examined in two etching systems, helicon and inductively coupled plasma ICP.. The trench profiles obtained from the ICP system were more tapered with thicker sidewall films compared to those from the helicon system. The trench etch profiles with Cl2rHBrrO2plasma in the ICP system appeared to be double-sloped. X-ray photoelectron spectroscopy XPS.analysis indicated that N2 addition to Cl2rHBrrO2plasma induced the formation of Si`N bonds in the sidewall films, in addition to the Si`O and Si`Br bonds observed with Cl2rHBrrO2. The sidewall films formed in Cl2rHBrrO2plasma showed higher oxygen intensities and chemical binding energies compared to those formed in Cl2rHBrrN2rO2 plasma. q2000 Elsevier Science B.V. All rights reserved.