Firing Stability of Polysilicon Passivating Contacts: The Role of Hydrogen
Firing Stability of Polysilicon Passivating Contacts: The Role of Hydrogen
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多晶硅钝化触点的烧成稳定性：氢的作用
DOI：
10.1109/pvsc43889.2021.9519080
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
D. Macdonald
中科院分区：
文献类型：
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作者：
D. Kang;H. Sio;J. Stuckelberger;D. Yan;Hieu T. Nguyen;T. Truong;Rong Liu;D. Macdonald
本研究比较了n型和p型多晶硅(polySi)/SiOx触点钝化后的n型硅片的燃烧响应，并使用各种表征工具，包括傅里叶变换红外光谱（FTIR）、二次离子质谱（SIMS）和微光致发光（µ- pl）光谱，评估了它们的性能变化。p型多晶硅表现出比n型多晶硅更好的热稳定性，特别是在800°C烧制时，这导致p型多晶硅触点的复合电流密度参数J0从12 fA/cm2增加到15 fA/cm2，而n型多晶硅触点的复合电流密度参数J0从8 fA/cm2增加到40 fA/cm2。FTIR测量表明，n型多晶硅触点的氢键密度增加，而p型多晶硅触点的氢键密度没有变化。SIMS结果表明，对于n型多晶硅，界面SiOx附近的氢浓度随着烧结温度的升高而增加，而p型多晶硅钝化触点的氢分布在不同的烧结温度下基本保持不变。推测n型和p型多晶硅的燃烧稳定性不同可能是由于燃烧时注入SiOx中间层的氢浓度不同，这可能是由氢扩散率的差异引起的。除氢外，其他影响，如缺陷的形成，也可能有助于燃烧影响，在n型和p型多晶硅触点中通过µpl检测到的a-Si:H信号减弱支持了这一点。
This work compares the firing response of n-type silicon wafers passivated by n- and p-type polysilicon (polySi)/SiOx contacts, and assesses the changes in their properties using various characterization tools, including Fourier-transform infrared spectroscopy (FTIR), secondary ion mass spectrometry (SIMS) and micro-photoluminescence (µ-PL) spectroscopy. Ptype poly-Si exhibits greater thermal stability than n-type poly-Si, particularly upon firing at 800°C, which results in an increase in the recombination current density parameter J0 from 12 to 15 fA/cm2 for the p-type poly-Si contacts, in comparison to a much larger increase from 8 to 40 fA/cm2 for n-type poly-Si contacts. FTIR measurements indicate that the n-type poly-Si contacts show an increased density of hydrogen bonds after firing, where no changes are observed in p-type poly-Si. SIMS results demonstrate that, for n-type poly-Si, the hydrogen concentration near the interfacial SiOx increases with the firing temperature, whereas the hydrogen profile remains largely unchanged in the p-type poly-Si passivating contacts upon various firing temperatures. It is speculated that the different firing stability of n- and p-type polySi might be due to the different hydrogen concentration injected into the SiOx interlayer upon firing, which could be caused by the difference in hydrogen diffusivity. In addition to hydrogen, other effects, such as the formation of defects, may also contribute to the firing impact, supported by the diminished a-Si:H signal detected by µ-PL in n- and p-type poly-Si contacts.