This study examined the effects of deposition temperature on Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films deposited using atomic layer deposition(ALD)with Tetrakis(ethylmethylamino)(TEMA)Hf,Zr,and cyclopentadienyl(CP)-linked ...This study examined the effects of deposition temperature on Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films deposited using atomic layer deposition(ALD)with Tetrakis(ethylmethylamino)(TEMA)Hf,Zr,and cyclopentadienyl(CP)-linked Hf,Zr precursors.The discrete feeding method was utilized to stabilize the growth per cycle,addressing challenges related to CP-linked precursors'high viscosity and molecular mass.The ALD temperature windows for HfO_(2)and ZrO_(2)films using the CP-linked precursors were 330-370℃and 290-330℃,respectively,higher than those using the TEMA precursors(250-280℃).Films deposited at higher temperatures with CP-linked precursors showed higher density and lower leakage currents than those with TEMA precursors,showing ferroelectric hysteresis loops from Hf_(0.5)Zr_(0.5)O_(2)(HZO)film at thicknesses as low as 5 nm without a wake-up process.In contrast,the film using TEMA precursor required a minimum thickness of 18 nm to exhibit similar properties.Crystallographic analysis revealed improved crystallization,larger grain sizes,and lower tensile stress in films deposited at higher temperatures.Also,in-situ crystallization was achievable for HZO films thicker than 6 nm when deposited at elevated temperatures.These findings demonstrate that higher temperature deposition by adopting CP-linked precursors enhances HZO thin film properties,making them suitable for advanced ferroelectric memory applications.展开更多
基金supported by SK hynix Inc.under its Center of Material Research for Semiconductors(C-MRS)program.
文摘This study examined the effects of deposition temperature on Hf_(0.5)Zr_(0.5)O_(2)(HZO)thin films deposited using atomic layer deposition(ALD)with Tetrakis(ethylmethylamino)(TEMA)Hf,Zr,and cyclopentadienyl(CP)-linked Hf,Zr precursors.The discrete feeding method was utilized to stabilize the growth per cycle,addressing challenges related to CP-linked precursors'high viscosity and molecular mass.The ALD temperature windows for HfO_(2)and ZrO_(2)films using the CP-linked precursors were 330-370℃and 290-330℃,respectively,higher than those using the TEMA precursors(250-280℃).Films deposited at higher temperatures with CP-linked precursors showed higher density and lower leakage currents than those with TEMA precursors,showing ferroelectric hysteresis loops from Hf_(0.5)Zr_(0.5)O_(2)(HZO)film at thicknesses as low as 5 nm without a wake-up process.In contrast,the film using TEMA precursor required a minimum thickness of 18 nm to exhibit similar properties.Crystallographic analysis revealed improved crystallization,larger grain sizes,and lower tensile stress in films deposited at higher temperatures.Also,in-situ crystallization was achievable for HZO films thicker than 6 nm when deposited at elevated temperatures.These findings demonstrate that higher temperature deposition by adopting CP-linked precursors enhances HZO thin film properties,making them suitable for advanced ferroelectric memory applications.
