Estimation of Interfacial Fixed Charge at Al2O3/SiO2 Using Slant-Etched Wafer for Solar Cell Application

Al2O3 with a negative fixed charge prepared by atomic layer deposition has been reported to improve surface passivation properties for Si-solar cell applications. The high negative fixed charge at the SiO2/Al2O3 interface facilitates a low surface recombination velocity and a high effective lifetime, which result in greater performance. In this study, we adopted an effective method using a slant-etched sample with various thicknesses of SiO2 to estimate the charge densities of both the bulk and interface of Al2O3 deposited by atomic layer deposition. We found a direct correlation between lifetime and total charge density in Al2O3, which are strong functions of film thickness and annealing condition.

[1]  J. Eikelboom,et al.  Low temperature surface passivation for silicon solar cells , 1996 .

[2]  Wmm Erwin Kessels,et al.  Ultralow surface recombination of c-Si substrates passivated by plasma-assisted atomic layer deposited Al2O3 , 2006 .

[3]  Wmm Erwin Kessels,et al.  Silicon surface passivation by atomic layer deposited Al2O3 , 2008 .

[4]  S. De Gendt,et al.  Estimation of fixed charge densities in hafnium-silicate gate dielectrics , 2006, IEEE Transactions on Electron Devices.

[5]  C. Voz,et al.  Crystalline silicon surface passivation with amorphous SiCx:H films deposited by plasma-enhanced chemical-vapor deposition , 2005 .

[6]  G. Lucovsky.  A chemical bonding model for the native oxides of the III–V compound semiconductors , 1981 .

[7]  P. Altermatt,et al.  Excellent passivation of highly doped p-type Si surfaces by the negative-charge-dielectric Al2O3 , 2007 .

[8]  Martin A. Green,et al.  Extended infrared response of silicon solar cells and the impurity photovoltaic effect , 1994, IEEE World Conference on Photovoltaic Energy Conference.

[9]  Jan Benick,et al.  High efficiency n-type Si solar cells on Al2O3-passivated boron emitters , 2008 .

[10]  P. Vitanov,et al.  Deposition and Properties of the Pseudobinary Alloy (Al2O3)x(TiO2)1-x and Its Application for Silicon Surface Passivation , 2006 .

[11]  I. Tanaka,et al.  Coordination and interface analysis of atomic-layer-deposition Al2O3 on Si(001) using energy-loss near-edge structures , 2003 .

[12]  Harold Dekkers,et al.  Very low surface recombination velocities on p-type silicon wafers passivated with a dielectric with fixed negative charge , 2006 .

[13]  Y.H. Kim,et al.  A capacitance-based methodology for work function extraction of metals on high-/spl kappa/ , 2004, IEEE Electron Device Letters.

[14]  I. Baumvol,et al.  Atomic transport and chemical stability during annealing of ultrathin Al2O3 films on Si. , 2000, Physical review letters.