Eur. Phys. J. E (2002) 8: 355-363
https://doi.org/10.1140/epje/i2001-10071-1

Hole nucleation in thin diblock copolymer films

¹ Université du Maine, UMR CNRS no 6515, ENSIM, BP 535, F-72085, Le Mans Cedex 9, France
² Institut Laue Langevin, 6 rue Jules Horowitz, BP 156, F-38042, Grenoble Cedex 9, France
³ Institut Charles Sadron, 6 rue Boussingault, 67083, Strasbourg Cedex, France

^* e-mail: ausserre@univ-lemans.fr

Received: 21 July 2001
Revised: 28 November 2001
Published online: 25 January 2014

Abstract

This paper reports an experimental study of a homogeneous nucleation process in the direct space, using an atomic-force microscope. Nucleated patterns are holes in a thin diblock copolymer film. The formation of nuclei from the metastable majority phase is followed either by the dissolution or by the growth of the hole. It is also preceded by the unexpected presence of a bump at the free surface. From the study of the nucleus surface topography at different stages of the evolution, we infer a description of the nucleation mechanism at a molecular level. It involves the existence of ordered metastable states characterized by the presence of compressed internal layers, the formation of pores in the center of the film, and the existence of interfacial flows across these pores. The presence of compressed internal layers was directly demonstrated using Neutron Reflectivity experiments, Our scheme is also consistent with all existing experimental data. After hole nucleation, we identify two distinct growth regimes: the first one is individual and the second one is interactive.