Tyndall brings chip breakthrough to home of silicon

16 Mar 2010

It’s fitting that the next major breakthrough in semiconductor research that could extend the life of Moore’s Law is being brought on a whistlestop tour of the largest chip manufacturers on the planet in the very place the silicon chip was born.

Last month, Tyndall revealed it had achieved a major breakthrough in nanotechnology, having designed and fabricated the world’s first junctionless transistor that could revolutionise microchip manufacturing in the semiconductor industry.

Prof Jean-Pierre Colinge’s breakthrough on the microchip transistor was published a month ago in Nature Nanotechnology, one of the most prestigious scientific research publications.

The Tyndall Institute’s Competence Centre for Applied Nanotechnology

The Tyndall Institute in November opened a €47.5m state-of-the-art Competence Centre for Applied Nanotechnology, an industry-led research initiative involving some of the world’s leading companies, such as multinationals Intel, Seagate, Medtronic and Analog Devices, and Irish companies Aerogen, Audit Diagnostics, Creganna and Proxy Biomedical, which is also supported by IDA Ireland.

The institute is this week participating in a Trade and Investment Mission led by the Taoiseach Brian Cowen TD. Enterprise Ireland, the Irish State agency responsible for the development and promotion of Ireland’s indigenous business sector, organised the mission.

Colinge’s team designed and fabricated a junctionless transistor that significantly reduces power consumption and greatly simplifies the IC manufacturing process.

Currently, all existing transistors are based upon junctions, which are formed when two pieces of silicon with different polarities are placed side by side. Controlling the junction allows the current in the device to be turned on and off, and it is the precise fabrication of this junction that determines the characteristics and quality of the transistor. It is also a major factor in the cost and complexity of semiconductor production.

No more junctions

Tyndall’s groundbreaking technology eliminates the need for a junction. Instead, the current flows in a very thin silicon wire and is perfectly controlled by a “wedding ring” structure that electrically squeezes the silicon wire in the same way that the flow of water through a hose can be controlled by squeezing the hose. These new structures are easy to fabricate, even at extremely small design nodes, thereby offering a significant potential to reduce manufacturing costs.

As design nodes shrink, minimising current leakage has become a significant challenge. The Tyndall junctionless devices have near-ideal electrical properties and behave like the most perfect transistors, thereby alleviating this challenge. In addition, they have the potential to operate at greater speeds and consume less energy than the conventional transistors used in today’s microprocessors.

Other work at Tyndall

In other developments, researchers at Tyndall are exploring the use of alternative semiconductor materials formed from the elements in Groups 3 and 5 of the periodic table. These elements, known as III-Vs, have superior properties to silicon and offer the possibility of building microchips with superior performance and greater energy efficiency than those produced today.

Fabricating fully operational III-V transistors will require combining III-V semiconductors with insulators of only a few atomic layers in thickness. To improve device performance, these insulating layers must have a high dielectric (high-k) constant.

One of the major challenges in fabricating III-V transistors is the ability to control the properties of the interface between the III-V semiconductor and the high-k layers. Researchers at Tyndall, led by Dr Paul Hurley, have recently developed a new process that results in a fourfold improvement in the electronic properties of this critical high-k/III-V interface that will reduce the voltage required to turn the transistor on and off.

By John Kennedy

Photo: A team at the Tyndall Institute has designed and fabricated a junctionless transistor that reduces power consumption and simplifies the IC manufacturing process

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years