Cambrios, U.S.: Uses Proteins to Form Fine Wires and Transparent Electrodes

The venture company U.S.-based Cambrios Technologies, Inc., which uses protein development and manufacturing technologies, has announced technology for LSI wiring processes, printed circuit board wiring processes using printing technology, and liquid crystal panel electrode manufacturing processes. The use of a solution eliminates the photolithography process and the film formation process using vacuum equipment, which simplifies the manufacturing process.

The LSI-oriented technology refers to the formation of an overcoat (cobalt) for controlling the electromigration of copper wiring. Using a phage containing a protein that binds only copper and a protein that binds only to cobalt, a cobalt layer is selectively formed on the copper wiring. First, the phage was bound around the cobalt particles, and as soon as the solution with the cobalt particles was applied to the wafer after the copper wiring was formed, the cobalt particles were bonded on the copper wiring (Fig. 1). According to the experimental results of Cambrios Co., cobalt particles do not substantially bond to the interlayer insulating film (low-k film) around the copper wiring. Using this method, the copper wiring that forms the cobalt layer was tested, and the electro-migration of copper was fully controlled as a result.

The technology for printed circuit boards refers to the use of printing methods to form copper wiring. Using a phage solution that binds copper atoms, a copper wiring is printed on a glass substrate or a plastic substrate using a screen printing technique, an inkjet technique, or the like. It is said that using this method, copper wiring can be formed at room temperature. Cambrios has now succeeded in forming copper wiring with a line width of approximately 100 μm on a plastic base plate (Fig. 2). For the wiring width and its accuracy, it is said that it depends on the printing technology.

The technology for LCD panels refers to the use of printing methods to form transparent electrodes. The purpose is to replace the existing ITO film used as a transparent electrode of a liquid crystal panel formed using a vacuum technique. Phages that bind metal materials are used. The company used this phage to form a transparent electrode with a thickness of about 100 nm on a plastic base plate at room temperature. As a result, a sheet resistance of 50 Ω/□ and a transmittance of 70% including a plastic substrate were obtained ( FIG. 3 ). The bacteriophage was first printed on a glass substrate, and when the temperature was treated at 300°C, the transmittance could be increased to about 87%. In the future, it is planned to reduce the sheet resistance and increase the transmittance by improving the manufacturing processes of bacteriophage, metal, and transparent electrodes. Details of phage-bound metal materials have not been disclosed, but it is claimed that there is no indium (In) in the metal material.

Source of information: pack.cn