Comparison of HfO2 films grown by atomic layer deposition using HfCl4 and H2O or O3 as the oxidant

HfO2 gate dielectric thin-films were deposited on Si wafers using an atomic-layer deposition (ALD) technique with HfCl4 and either H2O or O3 as the precursor and oxidant, respectively. Although the ALD reactions using either H2O or O3 were successfully confirmed at a deposition temperature of 300 °C, the structural and electrical properties of the HfO2 films grown using the two oxidants were quite different. The stronger oxidation power of the O3 compared to H2O increased the oxygen concentration in the HfO2 film and the rate of interfacial SiO2 formation even at the as-deposited state. Because of the larger oxygen concentration, the decrease in the capacitance density of the film grown with O3 after rapid thermal annealing at 750 °C under N2 atmosphere was slightly larger than that of the HfO2 film grown with H2O. Apart from this weakness, all the other electrical properties, including the fixed charge density, the interface trap density, the leakage current density and the hysteresis in the capacitance–...

[1]  Cheol Seong Hwang,et al.  Chemical interaction between atomic-layer-deposited HfO2 thin films and the Si substrate , 2002 .

[2]  R. Wallace,et al.  High-κ gate dielectrics: Current status and materials properties considerations , 2001 .

[3]  R. S. Johnson,et al.  Electron trapping in noncrystalline remote plasma deposited Hf-aluminate alloys for gate dielectric applications , 2002 .

[4]  In-Seok Yeo,et al.  Characteristics of n+ polycrystalline-Si/Al2O3/Si metal–oxide– semiconductor structures prepared by atomic layer chemical vapor deposition using Al(CH3)3 and H2O vapor , 2001 .

[5]  R. S. Johnson,et al.  Physical and electrical properties of noncrystalline Al2O3 prepared by remote plasma enhanced chemical vapor deposition , 2001 .

[6]  Ki-Young Oh,et al.  Improvement in Al2O3 dielectric behavior by using ozone as an oxidant for the atomic layer deposition technique , 2002 .

[7]  R. Fleming,et al.  High dielectric constant Hf–Sn–Ti–O thin films , 1999 .

[8]  C. Hwang,et al.  Thermal stability of atomic-layer-deposited HfO2 thin films on the SiNx-passivated Si substrate , 2002 .

[9]  Howard R. Huff,et al.  Physicochemical properties of HfO2 in response to rapid thermal anneal , 2003 .

[10]  Doo Young Yang,et al.  Interfacial reaction between chemically vapor-deposited HfO2 thin films and a HF-cleaned Si substrate during film growth and postannealing , 2002 .

[11]  C. Hwang,et al.  Effects of plasma nitridation of Al2O3 interlayer on thermal stability, fixed charge density, and interfacial trap states of HfO2 gate dielectric films grown by atomic layer deposition , 2003 .

[12]  Je-Hun Lee,et al.  Thermal stability and structural characteristics of HfO2 films on Si (100) grown by atomic-layer deposition , 2002 .

[13]  Jong-Ho Lee,et al.  Thermal annealing effects on the structural and electrical properties of HfO2/Al2O3 gate dielectric stacks grown by atomic layer deposition on Si substrates , 2003 .

[14]  Eric M. Vogel,et al.  Limitations of conductance to the measurement of the interface state density of MOS capacitors with tunneling gate dielectrics , 2000 .

[15]  Investigation of interface trap states in TiN/Al2O3/p-Si capacitor by deep level transient spectroscopy , 2003 .

[16]  A. Nakajima,et al.  Atomic-layer deposition of ZrO2 with a Si nitride barrier layer , 2002 .