Sub-?m thick rubber-elastic stamp on rigid support for high reliability microcontact printing
Microcontact printing (?CP) is very attractive as a low cost, high throughput, and sub-100-nm resolution lithography. However, macroscopic distortions (thermal expansion, swelling by the solvent-assisted procedure of inking, externally induced strain) as well as microscopic distortions (membrane relaxation in wide unsupported areas and merging of close features) compromise the quality of pattern transfer. We show that ultrathin (<1 ?m) poly-dimethylsiloxane (PDMS) stamps fabricated directly on flat rigid substrates are capable of printing high-resolution, high-quality patterns on areas larger than 1 cm2. Moreover, sagging effect is avoided even for patterns with very low filling ratio (5% of the surface). The absence of stamp distortions has allowed to demonstrate 1 ?m registration accuracy over areas of 55 mm2 in a mix and match process (?CP as a second step) using a homemade aligner.
microcontact printing alignment soft lithography