Nanometer scale patterning and pattern transfer on amorphous Si, crystalline Si, and SiO2 surfaces using self-assembled monolayers

Microcontact printing was used to form nanometer scale patterns of self-assembled monolayers (SAMs) on amorphous Si, crystalline Si, and SiO${}_2$ using octadecyltrichlorosilane (OTS) as the ink and an elastomer as the stamp. The patterns were subsequently transferred into crystalline Si substrates or amorphous Si films using the SAM of OTS as the resist film. Atomic force microscopy was used to characterize the quality of the SAM and the resulting patterns. Using a Si pillar structure as the master, “pancakes” of less than 80 nm in size were formed by over etching of the patterned OTS film on amorphous Si using KOH. The size of the resulting amorphous Si pancakes can be controlled by the etching time.