Impact of Tetrakis(ethylmethylamino)-based precursor and oxygen source selection on atomic layer deposition of ferroelectric HfxZr1-xO2 thin films

초록

As the semiconductor industry advances toward high-density, energy-efficient non-volatile memory, ferroelectric HfxZr1-xO2 (HZO) has emerged as a promising material due to its CMOS compatibility and scalability. This study presents a comprehensive comparison of precursor and oxidant selection impacts on atomic layer deposition (ALD) of ferroelectric HZO thin films. We evaluate H2O, O3, and H2O2 as oxidants, alongside supercycle (alternating HfO2 and ZrO2 ALD cycles) and cocktail precursors (1:1 mixture of tetrakis(ethylmethylamino)-Hf/Zr), examining ALD characteristics, chemical composition, and electrical properties. Oxidants demonstrated a bigger impact on film properties compared to precursors & sdot;H2O2-based HZO films show superior physical characteristics, including a 20% faster growth rate and 42% lower etch rate compared to O3. While supercycle films exhibit higher polarization (Pr) than cocktail films, H2O2 as oxidant yields the highest 2Pr in both methods, with significant increases of 22% among supercycle films and 44% among cocktail films compared to H2O. Notably, cocktail-H2O2 films show improved reliability with higher breakdown voltage and lower leakage current compared to all other combinations. This comprehensive analysis provides valuable insights into the use of cocktail precursors and H2O2 for high-quality HZO ALD, highlighting their potential for multicomponent ALD.

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