Negative charge and charging dynamics in Al(2)O(3) films on Si characterized by second-harmonic generation

作者：Gielis J J H^*; Hoex B; van de Sanden M C M; Kessels W M M

来源：Journal of Applied Physics, 2008, 104(7): 073701.

DOI：10.1063/1.2985906

Thin films of Al(2)O(3) synthesized by atomic layer deposition provide an excellent level of interface passivation of crystalline silicon (c-Si) after a postdeposition anneal. The Al(2)O(3) passivation mechanism has been elucidated by contactless characterization of c-Si/Al(2)O(3) interfaces by optical second-harmonic generation (SHG). SHG has revealed a negative fixed charge density in as-deposited Al(2)O(3) on the order of 10(11) cm(-2) that increased to 10(12)-10(13) cm(-2) upon anneal, causing effective field-effect passivation. In addition, multiple photon induced charge trapping dynamics suggest a reduction in recombination channels after anneal and indicate a c-Si/Al(2)O(3) conduction band offset of 2.02 +/- 0.04 eV.

• 出版日期2008-10-1