**1. Introduction**

Low‐temperature (LT) polycrystalline silicon (poly‐Si) on glass substrates is attractive for use as thin‐film transistors (TFTs) on the backplane of liquid crystal displays and organic light‐ emitting diode displays. It is well known that hydrogen impurities improve the performance and reliability of LT poly‐Si TFTs because they combine with the Si dangling bonds that affect the electrical properties of poly‐Si film and TFTs. Therefore, many hydrogenation techniques

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

such as hydrogen plasma [1–3], covering with a hydrogen‐containing film [4], and hydrogen ion implantation [5–7] were evaluated. However, the behavior of hydrogen atoms and their effects on the electronic and electrochemical properties of poly‐Si films are not clear yet. In this chapter, the behavior of hydrogen atoms in poly‐Si film is investigated in detail. In addition, we investigated the hydrogenation of LT poly‐Si TFTs from the perspective of the gettering phenomenon.
