Advanced Materials, Vol.18, No.4, 442-442, 2006
High-resolution patterning of molecular glasses using supercritical carbon dioxide
A glass-forming molecule. consisting of hexa(hydroxyphenyl)benzene [HHPB] protected with six tert-butoxycarbonyl (t-Boc) groups, is patterned and developed to produce features as small as 50 nm (see Figure) using supercritical CO2 (scCO(2)). Protected HHPB was shown to be completely soluble in scCO(2) without incorporation of either fluorine or silicon but could be rendered insoluble in scCO(2) by acid-catalyzed removal of the solubilizing t-Boc groups.