Interface recombination parameters of atomic-layer-deposited Al2O3 on crystalline silicon

Abstract

We measure the energy-dependent interface recombination parameters at the c-Si/Al2O3 interface using the frequency-dependent conductance technique. The hole capture cross section σp = (4 ± 3) × 10−16 cm2 is energy-independent, whereas the electron capture cross section σn shows a pronounced energy dependence and decreases from (7 ± 4) × 10−15 cm2 at midgap over two orders of magnitude toward the conduction band edge Ec. The capture cross section ratio at midgap is highly asymmetric with σn/σp = 5–70. The interface state density Dit is of the order of 1 × 1011 eV−1 cm−2 at midgap. Besides the main defect, a second type of defect with a capture cross section below 10−19 cm2 is resolved near the valence band edge. Numerical calculations of the injection-dependent effective surface recombination velocity using the measured interface recombination parameters show an excellent agreement with experimental data measured using the photoconductance technique.

Determination of interface states in metal(Ag,TiN,W)−Hf:Ta2O5/SiO N −Si structures by different compact methods

“…Detailed comparison of methods to quantify interface trap densities at dielectric/III-V semiconductor interfaces is given in [7]. In [8] it has been shown that frequencydependent conductance measurements give similar results to those obtained in [7] by C-V measurements. An attempt for reexamination of the extraction of MIS interface-state density by C-V stretchout and conductance methods has been recently done in [9].…”

Deposition temperature independent excellent passivation of highly boron doped silicon emitters by thermal atomic layer deposited Al2O3

“…On un-diffused samples (i.e., without a p þ diffusion) the fixed charge Q f as well as the defect distribution of the interface states D it (E) can be measured using traditional capacitance-voltage (C-V) measurements [25][26][27] or non-destructive corona charge/Kelvin probe measurements (contactless C-V). [28][29][30] On diffused samples, however, these measurements are no longer possible, as the applied corona charge will be screened by the highly conductive diffused layer, so that a transition from accumulation to inversion (which is needed for Q f and D it evaluation) can no longer be achieved.…”

Advanced modeling of the effective minority carrier lifetime of passivated crystalline silicon wafers

“…It was found that r p is energyindependent while r n is not at the interface between Al 2 O 3 and c-Si. 30 For simplicity, r n and r p were assumed to be energy-independent in all the simulations and fixed at 4 Â 10 À16 cm 2 . The fixed charge density of À1.3 Â 10 À13 cm À2 of our simulated Al 2 O 3 passivated samples was taken from the literature.…”