Registration accuracy in multilevel soft lithography

We investigate the registration accuracy achievable by multilevel soft lithography. By a specifically designed soft lithography aligner, we obtain, for the average misalignment between two registered patterned organic layers, values decreasing from (4.96 +/- 0.02) to (0.50 +/- 0.01) mu m upon increasing the Young's modulus of the stamp materials from 1.8 to 2600 MPa. This clearly identifies in the stamp distortions the main factor limiting the registration accuracy. The potentiality to achieve registration within 500 nm over areas of 50 x 50 mu m(2) is demonstrated, opening the way for soft lithographies with high overlay alignment accuracy.