What happens if the metal oxides used as channel in MOSFET? What happen to the conduction mechanism in the MOSFET? In MOSFET, oxides are used as gate dielectrics. Whether the oxides can be used as channel semiconductors?
There are many semiconducting oxides, one of the most common is SrTiO3 with an Eg~3.2 eV.
Unlike conventional semiconductors, achieving both p- and n-type doping in these materials is not straightforward. Therefore they are often used as normally-on transistors.
Examples:
Kumar, Kitoh & Inoue 2016
https://www.nature.com/articles/srep25789
Other transistors using oxide 2DEGs:
B. Förg, C. Richter, J. Mannhart, APL 100, 053506 (2012)
M. Hosoda, Y. Hikita, H.Y. Hwang, C. Bell, APL 103, 103507 (2013)
M. Boucherit, O. Shoron, C. Jackson, T. Cain, M.L.C. Buffon, C. Polchinski, S. Stemmer, S. Rajan, APL 104, 182904 (2014)
C. Woltmann, T. Harada, H. Boschker, V. Srot, P. A. van Aken, H. Klauk, J. Mannhart Phys. Rev. Appl. 4, 064003 (2015)
Circuits:
R. Jany, C. Richter, C. Woltmann, G. Pfanzelt, B. Förg, M. Rommel, T. Reindl, U. Waizmann, J. Weis, J.A. Mundy, D.A. Muller, H. Boschker, J. Mannhart, Adv. Mat. Int. 1, 1300031 (2014)
This article may help you .
https://patents.google.com/patent/US7462862B2/en
The problem is that most metal oxides have low charge carrier mobilities, hence are not well suited for creating a conductive channel.
Thank you Prof @Lior Kornblum , colleague @Chandra Bhal Singh and Prof. @Thomas Walther for the reply..
I have come across an article while I researching on this particular question of interest. I find that MOs as channel in TFT have been used from 1960s. First the Netherland Scientists Klasens and Koelmans (Klasens & Koelmans, 1964) first reported the MO TFT using tin oxide (SnO2) semiconductor. Followed by SnO2 TFT, polycrystalline MO materials such as indium oxide (In2O3) and zinc oxide (ZnO) were reported. The first ever reported amorphous MOs in 1954 is the vanadium pentoxide (V2O5) (Denton, Rawson, & Stanworth, 1954). For large area fabrication process, it was scientifically attractive but researchers didn’t notice its importance until 2003 invention on In-Ga-Zn-O, which impact the most for various applications.
The uses of MOs are better even than crystalline Si and III-V semiconductors. It owns unique properties such as highly transparent, excellent carrier mobilities even in the amorphous state, better photosensitivity, acts well as photoactive material and better mechanical properties. These MOs thin films are widely used in the inexpensive circuits due to the accessibility of high grade MOs using vapor or solution phase methods.
Dear Cyril,
Thank you for your fast review on using the conducting metal oxides as channels in the FETS.
This thin film transistor types are normally enhancement type where they are normally off and made on by a positive voltage on the gate to make the channel more conductive. They can not be made in a complementary form such as the case of silicon enhancement n and p MOSFETS. Therefore they are confined to specific applications such as in large area display. The other important factor is that whether they are scalable like the silicon transistors?
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Semiconductor