Introduction to Semiconductor Device Research

written by Prof. Sungsik Lee on 8 May 2017 (see more in Director’s Blog)


A semiconductor device research in the LEE lab consists of the following two parts which can also be accepted as a general classification in any semiconductor laboratory. One is the research on device physics, and the other is the development of the semiconductor technology.

  • Device physics research: This part becomes one of the research focuses in the LEE lab because of its importance for a local and fundamental breakthrough. This category of research is largely about theoretical investigations on operating principles and physical mechanims in the solid state semiconductor-based transistors, for example. Besides, what is the origin of the issues in transistors is another important angle of this category. For example, one of the modern types of transistors, such as TFTs, is usually having an instability issue upon bias and illumination stresses. So, many industries are trying to understand why it happens theoretically while being coupled with experiments to observe it. This leads to an efficient and effective solution to minimize it.  This eventually gives a local breakthrough for an existing technology (see our first research philosophy). More fundamentally, this device physics research may give us a theoretical background and clue for the next generation transistors besides MOSFETs or BJTs (see also the history of transistors). Indeed, there was one example for this in the category of passives though, which is the memristor. This was logically and theoretically deduced as a conceptual device in 1971 by Leon Chua, but now becomes real. In this respect, the LEE lab is trying theoretically to find a totally new device concept in the category of active devices.
  • Technology development: Within this research, there are two types: one is an advanced technology development for solving issues in current technologies, which better to collaborate with industries for effectiveness and efficiency in developments, just like what a semiconductor company has been doing to catch up with the Moore’s law. The other is to create a novel technology to replace the existing one which is ok for a certain specification though. In addition, in this second type, a new technology will be needed to be developed for a new type of active devices discussed above, leading to a more fundamental breakthrough. Here, the initial outcome can be a seed for the next generation in electronics, so industries could start with this and improve it in a much longer term.

*Note that those images are from the wikipedia on memristor and Moore’s law, respectively.