Mass production worthy HfO/sub 2/-Al/sub 2/O/sub 3/ laminate capacitor technology using Hf liquid precursor for sub-100 nm DRAMs

摘要

For the first time, we successfully demonstrated MIS capacitor with ALD (Atomic Layer Deposition) grown HfO/sub 2/-Al/sub 2/O/sub 3/ laminate film using Hf liquid precursor (Hf(NEtMe)/sub 4/) with EOT of 22.5 /spl Aring/ and acceptable leakage currents (1.0 fA/cell at 1.65 V) which is comparable to the smallest reported value. Advantages of Hf(NEtMe)/sub 4/ liquid precursor for DRAM capacitor dielectric are excellent step coverage (94% on high aspect ratio(<40:1)) and reasonable throughput (over two times higher than that of HfCl/sub 4/ solid precursor). This study will provide practical solution for chip-making industry in terms of mass production worthy process for sub-100 nm DRAM capacitor.