Viennese researchers test biocrystals for chip construction
Bacteria have the so-called S-layer as the outermost cell wall layer, which completely covers them. This layer, consisting of two-dimensional protein crystals, can be detached from the bacteria and broken down into its individual units. This results in various possible uses in medicine and technology, which are being investigated in a project supported by the Fund for the Promotion of Scientific Research (FWF) at the Center for Ultrastructure Research at the University of Natural Resources and Life Sciences (Boku) Vienna. In microelectronics, the combination of this biological crystal with silicon, the basic material for the manufacture of chips, promises significant improvements in performance. S layers that have been detached from the bacteria and broken down into their building blocks can recrystallize over large areas on suitable carrier surfaces, i.e. regain their regular shape. In addition to metal, plastic and carbon, silicon is one of these carriers. Silicon wafers are thin slices of this semiconductor that are cut into chips after electrical circuits have been applied. "By applying S layers to silicon wafers, we are combining a high-tech product of our time with an organism that has evolved in nature over the course of three billion years," explains Dietmar Pum from the Center for Ultrastructure Research, explaining the scientific approach to his research.
This compound produces an "advanced material" that can lead to significant improvements in microelectronics. This is because recrystallized S layers are strictly structured in lattice symmetries. These structures are used by the scientists as a matrix on a nanometer scale (one nanometer corresponds to about 10,000th of a human hair).
In this way, lines and squares with widths of 1000nm, 700nm, 400nm and 200nm can be produced on silicon wafers. With these lines, the metallic, microelectronic components are specifically positioned and arranged on the wafer.
"This specific property of the S-layers enables us to produce significantly smaller, electronic components with much finer structures, which are also significantly more powerful than those currently in use," summarizes Pum. According to Pum, these bio-electronic components could be produced industrially, e.g. as microprocessors, in around two years.
