Characterization and Fabrication of LPD-oxide GaAs MOS

• Main Authors: Ti-Kai Chao, 曹迪凱
• Other Authors: Meng-Chyi Wu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/36735704953445254251

碩士 === 國立清華大學 === 電子工程研究所 === 91 === Ⅲ-Ⅴ semiconductors have higher carrier mobility and better luminous characteristic compared with Ⅳ semiconductors, so it suits the application of high speed device and luminescent device. But it has been limited by the characteristic of its oxide, and by expensive fabrication for long time. In this paper, we used Liquid Phase Deposition technique with low cost, room-temperature, and high growth rate, to grow stably oxide on GaAs. This fabrication is cheaper than thermal oxidation and plasma enhanced chemical vapor deposition, and it has simpler fabrication processes, and it grows oxide at room temperature. Growth rate higher than 100nm/hr and LPD-oxide contains fluorine all prove the advantage of Liquid Phase Deposition. In this paper, we investigated the chemical compounds in solutions and temperature when growing oxide, how to affect growth rate, refractive index, breakdown electric field, leakage current density, flatband voltage shift, and effect charge density in oxide. We found the way to improve characteristic of LPD-oxide by observing the surface of oxide using SEM and analyzing chemical elements. To reform the quality of LPD-oxide by modifying the LPD method, optimizing the chemical compounds in solutions, controlling the temperature when growing oxide. We increased breakdown electric field up to 8.17MV/cm, reduced leakage current density down to 10-3A/cm at breakdown electric field is 4MV/cm. Flatband voltage shift was -0.4V, effect charge density in oxide was +2.25*1011/cm2 at 1MHz. We believe this low cost, low temperature, and high growth rate LPD method is a very good choice to grow oxide of Ⅲ-Ⅴ semiconductors in the future.