A number of lithography techniques like electron beam, ion beam, X-ray etc. are possible to use in order to pattern nanometric features. However they are too expensive for large scale production. Recently some new techniques have been developed known as Soft Lithography. Soft-litho means use of ‘soft materials’ i.e. polymers.
An elastomer of PDMS (poly dimethyl siloxane) of Sylgard 184, Dow Corning is used to prepare microstructures. There are different techniques used in soft lithography: Microcontact printing (CP), Replica molding (REM), Microtransfer molding (TM), Micromolding in capillaries (MIMIC), and Solvent assisted micromolding (SAMIM).
Introductory Nano (Soft) Lithography Using PDMS
This experiment involves synthesis of some micron size particles and then patterning them into small channels using micromolding in capillaries (MIMIC) technique. First we will discuss the synthesis of silica particles. Aim: To synthesize silica nanoparticles using a chemical route.
Tetraethyl orthosilicate (TEOS) [Si(OC2H5)4] 2. Ammonium hydroxide (NH4OH) 3. Distilled water (H2O) 4. Ethanol (C2H5OH) 14.9.2 Equipment 1. Round bottom flask 2. Magnetic stirrer 14.9.3 Synthesis Procedure