Thin film micro-scaled cold cathode structures of undoped and Si-doped AlN grown on SiC substrate with low turn-on voltage

• Published in: Chinese physics B Vol. 24; no. 5; pp. 587 - 591
• Main Author: 侍铭 陈平 赵德刚 江德生 郑军 成步文 朱建军 刘宗顺 刘炜 李翔 赵丹梅 王启明 刘建平 张书明 杨辉
• Format: Journal Article
• Language: English
• Published: 01.05.2015
• Subjects: 6H-SiC; AlN薄膜; Aluminum nitride; Cold cathodes; Current density; Electric fields; Field emission; Silicon carbide; Si掺杂; Thin films; Volt-ampere characteristics; 场发射特性; 导通电压; 微尺度; 金属有机化学气相沉积; 阴极结构
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/24/5/057901

The field emission characteristics of the AlN thin films with micro-scaled cold cathode structures are tested in the high vacuum system. The aluminum nitride （A1N） thin films with a thickness of about 100 nm are prepared on the n-type 6H-SiC （0001） substrate at 1100℃ by metal organic chemical vapor deposition （MOCVD） under low pressure. The I-V curves and surface micro-images of undoped and Si-doped AlN films are investigated. From the I-V and Fowler-Nordheim plots, it can be seen that the Si-doped AlN shows better field emission characteristics compared with the undoped AlN sample. The obtained turn-on field is 6.7 V/μm and the maximum emission current density is 154 mA/cm2 at 69.3 V for the Si- doped AlN film cathode after proper surface treatment. It is proposed that the relatively low electric resistivity of Si-doped AlN films is significant for electron migration to the surface region, and their rougher surface morphology is beneficial to a higher local electric field enhancement for the field emission.