Success in operation of transistor with channel length of 3 nm
In recent years, the increase in power consumption associated with the spread of mobile information terminals and the progress in IT devices has become a concern. Social demand for reduction of the power consumed by electronic information devices is increasing. Large scale integrated circuits (LSIs), the core of electronic information devices, contain over 100 million transistors that perform high-speed operations. In order to reduce the power consumption of information devices, it is necessary to develop technology that will decrease the energy consumed by these millions of transistors.
R&D has been conducted globally to reduce the energy consumed by transistors from a variety of perspectives such as materials, structure, and operational principles. In structure, an important design strategy is to miniaturize transistors. Today, some LSIs on the market are made up of transistors measuring approximately 20 nm. At an R&D level, the performance verification on transistors measuring smaller than 10 nm is attracting attention.
The developed technology was achieved employing the existing fabrication methods of semiconductors and incorporating a nanometer-scale structure-control technology and a new junction technology. Figure 1 shows the prototype procedures. A transistor was manufactured using an SOI substrate where a silicon single crystal is pasted onto an insulator film. First, an alkaline solution was used to dissolve a limited region of the single crystal to form a V-shaped groove. The dissolving speed varies significantly depending on the silicon crystal surface and, because of this property, only certain crystal surfaces remain, and a V-shaped groove is formed. By controlling the temperature and duration of dissolution, the tip of the groove can be made sharp, with a curvature radius of 3 nm. This part becomes the transistor channel. The channel thickness can be easily controlled by precisely adjusting the depth of the V-shaped groove.
- TAMS SEMICONDUCTOR LIMITED