Intel Turbo-Charging Transistors
December 10, 2009 - Intel has reached a milestone in its quest to make transistors switch ever faster while using less energy, by integrating a high-k gate with a compound semiconductor transistor. Details were presented this week at the International Electron Devices Meeting (IEDM). Intel has been researching the possibility of replacing the silicon channel of the transistor by a compound semiconductor material such as indium gallium arsenide (InGaAs). Up until recently, such transistors used a Schottky gate with no gate dielectric, and were subjected to large gate leakage. Intel has now identified and integrated a high-k gate dielectric to reduce leakage with these so-called QWFETs (quantum well field effect transistors). The prototype device was fabricated on a silicon wafer substrate, pointing towards eventual process synergy with the existing silicon infrastructure. By using a high-k dielectric, gate leakage for short channel devices was reduced by 1000x compared with a Schottky gate, while the electrical oxide thickness was reduced by 33%, leading to higher switching speeds, which in turn leads to improved chip performance. More details are available in a blog by Mike Mayberry.
"In this blog, I’ll update the progress and give a look ahead to some of the upcoming research projects.
First as a reminder, unlike silicon, a compound semiconductor is made up of two or more elements, indium, gallium and arsenic for example (InGaAs). Using two or more elements means more opportunity to tune the materials for performance or optical properties but also makes the challenge of fabricating wafers and processing much more complicated. Today, compound semiconductors are used in smaller scale applications where their special properties outweigh the added costs. Our goal is to take advantage of the vastly larger spending on silicon infrastructure and put it to use fabricating compound semiconductor devices."