ALD and Parasitic Growth Characteristics of the Tetrakisethylmethylamino Hafnium ( TEMAH ) / H2O Process
ALD and Parasitic Growth Characteristics of the Tetrakisethylmethylamino Hafnium ( TEMAH ) / H2O Process
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四乙基甲基氨基铪 (TEMAH)/H2O 工艺的 ALD 和寄生生长特性
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
S. Gendt
中科院分区：
文献类型：
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作者：
L. Nyns;A. Delabie;J. Swerts;S. Elshocht;S. Gendt
互补金属氧化物半导体器件的不断缩小要求集成Hf基高k材料作为通过原子层沉积（ALD）沉积的栅极半导体。当使用四乙基甲基氨基铪（TEMAH）作为金属前体来存款这种Hf基材料时，其有限的热稳定性可导致前体分解。本文研究了在285-365 °C温度范围内，前驱体分解对TEMAH/H2O ALD生长行为的影响以及HfO 2沉积层的性质。在此温度范围内，由于寄生生长，TEMAH脉冲在高达10 s的脉冲长度下不会饱和。当化学吸附的TEMAH配体分解并且新引入的前体分子与这些分解的表面位点反应时，发生寄生生长。TEMAH/N2反应循环的重复证明了这种不受控制的生长的存在，导致沉积质量差的Hf基层，而其贡献取决于反应温度和TEMAH脉冲长度。最后，还需要严格控制H2O脉冲，因为太长的脉冲会导致温度诱导的表面脱羟基作用，使TEMAH/H2O工艺的GPC在285°C下降低高达~ 12%。
The continuous downscaling of complementary metal oxide semiconductor devices has required the integration of Hf-based high-k materials as gate dielectrics deposited by atomic layer deposition (ALD). When tetrakisethylmethylamino hafnium (TEMAH) is used as the metallic precursor to deposit such Hf-based materials, its limited thermal stability can result in precursor decomposition. This paper shows to what extent precursor decomposition affects the growth behavior of the TEMAH/H 2 O ALD in the temperature range 285-365 °C as well as the properties of the deposited HfO 2 layer. In this temperature range, the TEMAH pulse does not saturate up to pulse lengths of 10 s due to parasitic growth. Parasitic growth occurs when chemisorbed TEMAH ligands decompose and newly introduced precursor molecules react with these decomposed surface sites. The existence of such uncontrolled growth was proven by the repetition of TEMAH/N 2 reaction cycles, resulting in the deposition of a poor-quality Hf-based layer, while its contribution depends on both the reaction temperature and the TEMAH pulse length. Finally, also the H 2 0 pulse needs to be strictly controlled because too long pulses result in temperature-induced dehydroxylation of the surface, lowering the GPC of the TEMAH/H 2 O process with up to ~ 12% at 285°C.