Abstract Metal--insulator--metal (MIM) capacitors with atomic-layer-deposited Al$_{2}$O$_{3}$ dielectric and reactively sputtered TaN electrodes in application to radio frequency integrated circuits have been characterized electrically. The capacitors exhibit a high density of about 6.05 fF/$\mu $m$^{2}$, a small leakage current of $4.8\times 10^{-8}$ A/cm$^{2}$ at 3 V, a high breakdown electric field of 8.61 MV/cm as well as acceptable voltage coefficients of capacitance (VCCs) of 795 ppm/V$^{2}$ and 268 ppm/V at 1 MHz. The observed properties should be attributed to high-quality Al$_{2}$O$_{3}$ film and chemically stable TaN electrodes. Further, a logarithmically linear relationship between quadratic VCC and frequency is observed due to the change of relaxation time with carrier mobility in the dielectric. The conduction mechanism in the high field ranges is dominated by the Poole--Frenkel emission, and the leakage current in the low field ranges is likely to be associated with trap-assisted tunnelling. Meanwhile, the Al$_{2}$O$_{3}$ dielectric presents charge trapping under low voltage stresses, and defect generation under high voltage stresses, and it has a hard-breakdown performance.
Received: 18 October 2006
Revised: 05 December 2006
Accepted manuscript online:
Fund: Project supported by the
National Natural Science Foundation of China (Grant No
90607023), Shanghai Pujiang Program (Grant No 05PJ14017), SRF
for ROCS, SEM, and the Micro/Nano-electronics Science and
Technology Innovation Platform (985) and the Ministry of
Education of China in the International Research Training Group
``Materials and Concepts for Advanced Interconnects".
Cite this article:
Ding Shi-Jin(丁士进), Huang Yu-Jian(黄宇健), Huang Yue(黄玥), Pan Shao-Hui(潘少辉), Zhang Wei(张卫), and Wang Li-Kang(汪礼康) High density Al2O3/TaN-based metal--insulator-- metal capacitors in application to radio frequency integrated circuits 2007 Chinese Physics 16 2803
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