A study on SnO thin films and SnO diodes using infrared rapid thermal annealing process

• Main Authors: Yu-Hao Jiang, 蔣宇皓
• Other Authors: Jian-Zhang Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/05879170280265527968

碩士 === 國立臺灣大學 === 應用力學研究所 === 103 === This thesis reports the tin monoxide (SnO) thin films that were deposited by RF-sputtering technique and post-annealed by infrared rapid thermal furnace (hereafter referred to as RTA). We investigated the crystallinity, surface morphology, chemical composition, optical properties, electrical properties and electromechanical properties of tin monoxide thin film post-annealed at 225, 245, and 265 °C for 2.5, 5, 7.5, 10 min in air ambient. SnO thin films were then used for the Schottky diodes and the PIN diodes. 120-nm-thick SnO thin films were sputter-deposited on glass substrates without intentional heating on the substrate. X-ray diffraction analyses indicate the existence of metallic Sn and SnO phases in the films. The preferred orientation of SnO crystals are (110) and (101). Metallic Sn particles and strip-wise features appeared in the samples annealed at lower temperature, as evidenced by SEM and AFM results. The EPMA results demonstrate that the [Sn]/[O] atomic ratio of SnO thin films about 70/30 and XPS results reveal that SnO phase is the dominant phases after RTA processes. The Tauc’s bandgap is calculated as 1.8 eV for as-deposited and increases to ~2.8 eV after RTA processes. P-type conductivity is confirmed for all RTA-processed films by Hall and Seebeck coefficient measurement. The best achieved hole mobility is 0.825 cm2 V-1 s-1 for SnO thin films annealed at 245°C for 2.5 min and the mobility value decreases as RTA duration increases. In either stretching test or bending test, the SnO thin films annealed at 265°C showed the best electrical stability under same mechanical strain. The SnO films were then successfully used for the Schottky and PIN diodes. Rectifying characteristic was clearly demonstrated with rectified values of 38.0 and 66.1, respectively.