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In situ Photoluminescence Study of Plasma Effects on Passivation of Crystalline Silicon Coated with Aluminum Oxide
Author(s) -
Sreng Mengkoing,
Silva François,
Roca i Cabarrocas Pere
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201800612
Subject(s) - passivation , photoluminescence , materials science , silicon , crystalline silicon , plasma enhanced chemical vapor deposition , plasma , silicon oxide , silicon nitride , wafer , analytical chemistry (journal) , amorphous silicon , amorphous solid , atomic layer deposition , chemical engineering , layer (electronics) , nanotechnology , optoelectronics , chemistry , crystallography , environmental chemistry , physics , quantum mechanics , engineering
A degradation of crystalline silicon surface passivation provided by aluminum oxide (Al 2 O 3 ) is generally observed after plasma processes, e.g., deposition of amorphous silicon nitride. To minimize such detrimental effect, a better understanding of the interaction between plasma species and the Al 2 O 3 layer is required. Using in situ photoluminescence, the passivation quality of as‐deposited and annealed crystalline silicon wafers coated with Al 2 O 3 grown by atomic layer deposition is characterized in real time during argon‐hydrogen plasma exposure. The photoluminescence intensity of as‐deposited samples instantly steps up after the plasma ignition, and then it gradually decreases as a function of plasma exposure time. However, only degradation of photoluminescence signal can be found if the samples are annealed prior to the plasma treatment. The interaction between vacuum UV light from plasma and different types of chemical bonds in the Al 2 O 3 layer is proposed to explain the obtained results. Understanding the mechanisms and root cause leading to different behavior between as‐deposited and annealed samples under plasma exposure is a first step toward redesigning the process flow for better surface passivation.