The Fabrication and Electrical Properties of Metal/HfO2/Si(p-type)Field-Effect Transistors

• Main Authors: Yen-wen Chen, 陳彥文
• Other Authors: Shih-chih Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/96372923945364110914

碩士 === 國立雲林科技大學 === 光學電子工程研究所 === 95 === HfO2 thin films with a thickness of 70Å were deposited on p-Si (100) substrate by RF sputtering at 400℃. Si3N4 and SiNO very thin layers will be grown by using N2 plasma to bombard heated Si substrate or sputtering system with Si3N4 target. The Si3N4 and SINO layers might be as barrier to forbid out-diffusion of oxygen and silicon atoms to promote the MIS performance. HfO2 films were exposed under oxygen plasma with different duration . The improvement was suggested to be due to the elimination of oxygen vacancies by oxygen plasma surface treatment. Under elimination of oxygen vacancies process, the ultra thin oxide shows high quality and small interfacial trap density. To compare among these samples, the dielectric for a film after N2 plasma treatment 3 minutes , HfO2 films were in-situ under oxygen plasma 3 minutes and 3 minutes furnace annealed at 650℃ increased to 23.7 and its leakage current density lowered to 1.59 × 10-7A/cm2 and 3.23× 10-6A/cm2 at positive and negative applied voltages of 1.5 V, respectively. The Si3N4 layers might be as barrier to forbid out-diffusion of oxygen and silicon atoms, the improvement was suggested to be due to the elimination of oxygen vacancies by oxygen plasma surface treatment to promote the MIS performance and decrease leakage current density. The dominant leakage mechanisms are the Schottky Emission at low electric field , the Poole-Frenkel at high electric field and the Fowler-Nordheim Tunneling at high electric field.