MIM capacitors using atomic-layer-deposited high-/spl kappa/ (HfO/sub 2/)/sub 1-x/(Al/sub 2/O/sub 3/)/sub x/ dielectrics |
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Authors: | Hang Hu Chunxiang Zhu Xiongfei Yu Chin A. Li M.F. Byung Jin Cho Dim-Lee Kwong Foo P.D. Ming Bin Yu Xinye Liu Winkler J. |
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Affiliation: | Silicon Nano Device Lab., Nat. Univ. of Singapore, Singapore; |
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Abstract: | Metal-insulator-metal (MIM) capacitors with (HfO/sub 2/)/sub 1-x/(Al/sub 2/O/sub 3/)/sub x/ high-/spl kappa/ dielectric films were investigated for the first time. The results show that both the capacitance density and voltage/temperature coefficients of capacitance (VCC/TCC) values decrease with increasing Al/sub 2/O/sub 3/ mole fraction. It was demonstrated that the (HfO/sub 2/)/sub 1-x/(Al/sub 2/O/sub 3/)/sub x/ MIM capacitor with an Al/sub 2/O/sub 3/ mole fraction of 0.14 is optimized. It provides a high capacitance density (3.5 fF//spl mu/m/sup 2/) and low VCC values (/spl sim/140 ppm/V/sup 2/) at the same time. In addition, small frequency dependence, low loss tangent, and low leakage current are obtained. Also, no electrical degradation was observed for (HfO/sub 2/)/sub 1-x/(Al/sub 2/O/sub 3/)/sub x/ MIM capacitors after N/sub 2/ annealing at 400/spl deg/C. These results show that the (HfO/sub 2/)/sub 0.86/(Al/sub 2/O/sub 3/)/sub 0.14/ MIM capacitor is very suitable for capacitor applications within the thermal budget of the back end of line process. |
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