Process prints silicon circuits

Although flat-panel displays are less expensive than they were a few years ago, they are still relatively expensive as electrical appliances go. One of the main costs of manufacturing active-matrix liquid crystal displays is making the screen's backplane, which contains as many transistors as the screen has pixels.

Researchers from Princeton University have demonstrated a way to use a flexible stamp to print these thin-film transistors. The usual photolithography process etches layers of methyl, semiconductor and insulator using chemicals and light.

The researchers' method prints a single polymer mask on the layered materials, which made it possible to etch the transistor's features without needing to alter each layer with light.

The printing process is also poised to enable new types of large-area electronics such as screens that encompass walls or floors, according to the researchers.

The printing process could also be used with organic, or plastic, transistors, which are comparable in performance to and potentially cheaper than the amorphous silicon transistors used today.

The researchers' eventual goal is to directly print electronics on flexible surfaces.

Printing thin film transistors could be introduced into manufacturing processes within five years, according to the researchers. The work appeared in the October 13, 2003 issue of Applied Physics Letters.