Pattern profile distortion of nanoporous organosilicates has been investigated after pattern transfer processes. After photoresist stripping with O-2-plasma ashing, many organic function groups are destroyed and sequentially transformed into siloxanol groups (Si-OH) in the nanoporous organosilicates. The interaction between siloxanol groups and the gelation reaction occurred in the internal porous organosilicates predominate stress evolution, leading to the deformation of patterned porous organosilicate films. This physical mechanism responsible for pattern distortion and stress evolution can be consistently confirmed through the residual stress vs. temperature measurement and Fourier transform infrared spectroscopy. (C) 2003 The Electrochemical Society.