Solution-Processed Silicon Doped Tin Oxide Thin Films and Thin-Film Transistors Based on Tetraethyl Orthosilicate

Abstract

Recently, tin oxide (SnO2) has been the preferred thin film material for semiconductor devices such as thin-film transistors (TFTs) due to its low cost, non-toxicity, and superior electrical performance. However, the high oxygen vacancy (VO) concentration leads to poor performance of SnO2 thin films and devices. In this paper, with tetraethyl orthosilicate (TEOS) as the Si source, which can decompose to release heat and supply energy when annealing, Si doped SnO2 (STO) films and inverted staggered STO TFTs were successfully fabricated by a solution method. An XPS analysis showed that Si doping can effectively inhibit the formation of VO, thus reducing the carrier concentration and improving the quality of SnO2 films. In addition, the heat released from TEOS can modestly lower the preparation temperature of STO films. By optimizing the annealing temperature and Si doping content, 350 °C annealed STO TFTs with 5 at.% Si exhibited the best device performance: Ioff was as low as 10−10 A, Ion/Ioff reached a magnitude of 104, and Von was 1.51 V. Utilizing TEOS as an Si source has a certain reference significance for solution-processed metal oxide thin films in the future.

Dual Role of AgNO3 as an Oxidizer and Chloride Remover toward Enhanced Combustion Synthesis of Low-Voltage and Low-Temperature Amorphous Rare Metal-Free Oxide Thin-Film Transistors

“…Si doping can also help reduce the oxygen vacancies in the metal oxide film due to its higher bond dissociation energy with oxygen (798 kJ/mol for Si–O and 547 kJ/mol for Sn–O) . Several studies have doped SnO 2 with Si and reported oxygen-vacancy suppression and improved TFT performance. , Making the film amorphous not only is relevant to achieving a uniform film quality but also allows for an easy wet etching process that can help create the pattern of the active channel layer. Additionally, the thickness values of the two films were not significantly different: 11 nm for the NH 4 NO 3 -assisted Si x Sn y O film and 9 nm for the AgNO 3 -assisted Si x Sn y O film.…”