A portable and compact photolithography system based on a solid-state light source of UV light-emitting diodes (LEDs) is described. Solid-state photolithography can achieve high-quality patterns over a wide range of length scales at a fraction of the cost of contact mask aligners. 2D nanoscale and 1D microscale patterns can easily be created.
While photolithography has enabled the development of microelectromechanical systems (MEMS) and other “micro machines”, the extremely high-cost of producing such structures has limited further advances. The lab of Teri Odom has addressed these limitations by using GaN-based LEDs in place of inefficient and expensive Hg-vapor lamps for solid-state photolithography. This advance substantially lowers both the up-front cost of the equipment as well as the operational costs associated with maintaining and powering these systems. The Odom group has shown that this benchtop photolithography system can produce patterns as small as 200 nm over 4 in. Si wafers in a single exposure and has already used this technology to create a multitude of patterns and devices.
Nanowerk – The solid-state photolithography system (SSP) is a low-cost (as low as $30 for 2 inch wafers) and compact (about 0.003 m3 and less than 1 kg) system that can be built from off-the-shelf parts and operated on the bench-top. A 200-LED system can be used with industry standard 4-in wafers (at a cost of $400).
Featured Research: Photolithography on the Benchtop
Solid-state photolithography (SSP) enables the capabilities of one of the most important tools in nano- and microfabrication, the mask aligner, to be performed on the benchtop. SSP can create patterns over a wide range of different length scales (down to several hundred nanometers) and over macroscale areas at a fraction of the cost of current instruments. The design of the SSP system alleviates the need for dedicated power supplies, vacuum lines, and cooling systems, and thus makes SSP a compact and portable photolithography option. The cover image is a close-up of the ultraviolet light-emitting diode (LED) array that is used as the solid-state light source for SSP.