This overview of Imprinting is designed to summarize the key elements of imprint processing as a device fabrication technology. Devices can be anything from a simple diffraction grating to a complex microprocessor. The key elements are;
Imprinting describes a number of moulding techniques for creating patterns on substrates, one is shown on the right. For an explanation of the other different imprint processes and the challenges of dealing with product wafers go to Imprint Essentials
Multiple types of imprinted features are illustrated on the right and can be;
part of the device - a functional application such as micro-lenses
used to pattern an underlying device and then stripped - a resist application such as CMOS circuit fab.
a single molecular layer- a transfer printing application such as making a bio "lab on a chip"
A wide range of structures have been imprinted from 2 nm nano-features, 3 D bridge structures, micro lenses and microfluidic devices. For some examples of imprinted features go to Patterns
Imprint has been used as low cost mass production process for credit card holograms since 1982. More on the History of imprint.
Imprint is just one small step in device fabrication. Device fabrication is a method that converts a starting state (blank substrate) to a finishing state (device). For more on Device Fabrication.
Key requirements for any patterning application are;
The Imprint Process must be designed to meet the requirements of the specific application for example;
Integrated circuits require sub 50 nm overlay and defect densities of less than 5 per wafer - demands step and repeat (S&R) patterning at room temperature with the lowest possible viscosity materials. For more go to.
Patterning the surface of a film with no overlay requirement - demands thermal imprinting without any additional imprint material.