IBM's Breakthrough in Computer Chip Manufacturing

(Photo Courtesy: IBM )

Today IBM announced the first-ever application of a breakthrough self-assembling nanotechnology to conventional chip manufacturing, borrowing a process from nature to build the next generation computer chips.

Self assembly is a concept scientists have been studying at IBM and in labs around the world as a potential technique to create materials useful for building computer chips. The concept occurs in nature every day, it is how enamel is formed on our teeth, the process that creates seashells and is what transforms water into complex snowflakes. The major difference is, while the processes that occur in nature are all unique, IBM has been able to direct the self-assembly process to form trillions of holes that are all similar.

Today, chips are manufactured with copper wiring surrounded by an insulator, which involves using a mask to create circuit patterns by beaming light through the mask and later chemically removing the parts that are not needed. The new technique to make airgaps by self-assembly skips the masking and light-etching process. Instead IBM scientists discovered the right mix of compounds, which they pour onto a silicon wafer with the wired chip patterns, then bake it.

In the new method, IBM researchers coated a mixture of two polymers over the top of a silicon wafer. The two types of molecules in the coating, which were created from scratch by the scientists using component chemicals, then assembled themselves into a thin film pocked with evenly-spaced holes that contain no air. These vacuum spaces, sized 20 nanometers across and spaced 40 nanometers apart, act like molecule-sized versions of the vacuum tubes that once helped insulate mainframe computers and televisions.

This new form of insulation, commonly referred to as “airgaps” by scientists, is a misnomer, as the gaps are actually a vacuum, absent of air. A vacuum is believed to be the ultimate insulator for what is known as wiring capacitance, which occurs when two conductors, in this case adjacent wires on a chip, sap or siphon electrical energy from one another, generating undesirable heat and slowing the speed at which data can move through a chip. The technique deployed by IBM causes a vacuum to form between the copper wires on a computer chip, allowing electrical signals to flow faster, while consuming less electrical power. The self-assembly process enables the nano-scale patterning required to form the gaps; this patterning is considerably smaller than current lithographic techniques can achieve.

In chips running in IBM labs using the technique, the researchers have proven that the electrical signals on the chips can flow 35% faster, or the chips can consume 15% less energy compared to the most advanced chips using conventional techniques.

The IBM patented self-assembly process thus moved a nanotechnology manufacturing method that had shown promise in laboratories into a commercial manufacturing environment for the first time, providing the equivalent of two generations of Moore's Law wiring performance improvements in a single step, using conventional manufacturing techniques.

IBM said it completed a successful demonstration of the process in a run at its East Fishkill, N.Y., chip fabrication plant, and plans to use the new self-assembly method, in commercial-scale, server-chip production lines by 2009.