결정질 실리콘 태양전지의 패시베이션 적용을 위한 Al2O3/SiON 적층구조의 열적 안정성에 대한 연구 = A Study on the Thermal Stability of an Al2O3/SiON Stack Structure for c-Si Solar Cell Passivation Application

다국어 초록 (Multilingual Abstract)

We investigated the influence of blistering on Al2O3/SiON stacks and Al2O3/SiNx:H stacks passivation layers. Al2O3 film providesoutstanding Si surface passivation quality. Al2O3 film as the rear passivation layer of a p-type Si solar cell is usually stacked with acapping layer, such as SiO2, SiNx, and SiON films. These capping layers protect the thin Al2O3 layer from an Al electrode during theannealing process. We compared Al2O3/SiON stacks and Al2O3/SiNx:H stacks through surface morphology and minority carrierlifetime after annealing processes at 450oC and 850oC. As a result, the Al2O3/SiON stacks were observed to produce less blisterphenomenon than Al2O3/SiNx:H stacks. This can be explained by the differences in the H species content. In the process of depositingSiNx film, the rich H species in NH3 source are diffused to the Al2O3 film. On the other hand, less hydrogen diffusion occurs in SiONfilm as it contains less H species than SiNx film. This blister phenomenon leads to an increase insurface defect density. Consequently,the Al2O3/SiON stacks had a higher minority carrier lifetime than the Al2O3/SiNx:H stacks.

참고문헌 (Reference)

1 B. Kafle, "Thermal Stability Investigations of PECVD Al2O3 Fiim Discussing a Possibilty of Improving Surface Passivation by Re-hydrogenation after High Themperature Processes" 1788-1792, 2012

2 Y.-T. Kim, "The Effect of RF Power and SiH4/(N2O+N2) Ratio in Properties of SiON Thick Film for Silica Optical Waveguide" 38 (38): 1150-1154, 2001

3 G. Dingemans, "Stability of Al2O3 and Al2O3.a-SiNx:H Stacks for Surface Passivation of Crystalline Silicon" 106 : 114907-, 2009

4 Paul F. Becher, "Recent Advances in Microstructural Tailoring of Silicon Nitride Ceramics and the Effects on Thermal Conductivity and Fracture Properties" 한국세라믹학회 42 (42): 1-20, 2005

5 M. I. Alayoa, "On the Nitrogen and Oxygen Incorporation in Plasma-enhanced Chemicalvapor Deposition (PECVD)SiOxNy Films" 402 (402): 154-161, 2002

6 V. Naumanna, "Interface and Material Characterization of Thin ALD-Al2O3 Layers on Crystalline Silicon" 2012

7 S. Kühnhold, "Impact of Thermal Treatment on PECVD Al2O3 Passivation Layers" 27 : 273-279, 2012

8 J. Dupuis, "Impact of PECVD SiON Stoichiometry and Postannealing on the Silicon Surface Passivation" 516 (516): 6954-6958, 2008

9 G. Dingemans, "Hydrogen Induced Passivation of Si Interface by Al2O3 Films and SiO2/Al2O3 Stacks" 97 (97): 152106-, 2010

10 S. Jakschik, "Crystallization Behavior of Thin ALD-Al2O3Films" 425 (425): 216-220, 2003

11 B. Vermang, "Blistering in ALD Al2O3 Passivation Layers as Rear Contacting for Local Al BSF Si Solar Cells" 101 : 204-209, 2012

12 T. Lüdera, "Al2O3/SiNx-Stacks at Increased Temperatures:Avoiding Blistering During Contact Firing" 27 : 426-431, 2012

13 김재범, "ALD법으로 제조된 Al2O3막의 유전적 특성" 한국진공학회 11 (11): 183-188, 2002