Combinatorial study of surface pattern formation in thin block copolymer films.
Surface pattern formation in diblock copolymer films is investigated as a function of film thickness h and molecular mass M. Smooth films are observed for certain h ranges centered about multiples of the lamellar thickness L0, and we attribute this effect to an increase in the surface chain density with h in the outer brushlike copolymer layer. We also observe apparently stable labyrinthine surface patterns for other h ranges, and the average size of these patterns is found to scale as lambda approximately L0(-2.5). Hole and island patterns occur for h ranges between those of the labyrinthine patterns and the smooth regions, and their size similarly decreases with L0 and M.
Smith
A P
AP
Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
Douglas
J F
JF
Meredith
J C
JC
Amis
E J
EJ
Karim
A
A