Specific Process Knowledge/Imprinting

Imprinting

Imprinting (hot embossing) is a parallel transfer of a pattern made by a serial technique (often e-beam). First a stamp is made, usually in Si or SiO${\rm {_{2}}}$ however other materials could also be used. The pattern on the stamp is then transferred to a polymer (on a different substrate), by heating both stamp and substrate to above the glass transition temperature T$_{g}$ of the polymer and then pressing the stamp and the substrate together, hence deforming the polymer on the substrate. The stamp and substrate are then cooled down and only separated when the temperature is well bellow T$_{g}$ of the polymer. Normally the stack is often cooled to room temperature to easily separate the two parts.

After the stamp has been removed it is possible to use the polymer as e.g. an etch mask in a dry etch to transfer the patters from the stamp to the substrate.

It is necessary to deposit anti stiction coating on the stamp to ensure that it can be separated from the substrate, this is done in either the MVD or the ASE. If the stamp it not anti stiction coated it is likely that either (or both) the stamp and substrate will break during separation. It is only necessary to deposit anti stiction coating on the stamp one time even though it is used a multiple of times.

Choose an equipment

• MVD - Molecular Vapor Deposition - Antistiction coater for silicon stamps
• Drop Shape Analyzer - Tool to measure the hydrophobicity of the antistiction layer
• EVG NIL - Aligner and imprinting tool