Different passivation layers on phosphorous diffused emitters have been studied. A comparison between silicon nitride (SiN_x) single layer at different deposition temperatures, stacks of “outgassing” silicon oxide (that was grown during the moving in/out of the furnace in ambient air during the outgassing process) and an ultrathin SiO_x layer formed by plasma oxidation capped with SiN_x layers have been investigated. Optimization of plasma enhanced chemical vapor deposition (PECVD) SiN_x at different deposition temperatures showed good passivation quality depending on the hydrogen content. Plasma oxidation process by a PECVD tool without utilizing a silicon source in the process gas flow is an obvious choice to form a thin SiO_x as it allows the formation of a SiO_x/SiN_x stack in a sequence of deposition processes in the same inline PECVD tool. Such an ultrathin SiO_x layer was found to not only improve the surface passivation after a fast firing process but also to maintain the excellent anti-reflection coating (ARC) property of the SiN_x. Low emitter saturation current density J_0e values of 15 fA/cm² for planar and 24 fA/cm² for textured surfaces for an emitter with a sheet resistivity of 161 Ω/ sq has been reached after firing at 850 °C, which is comparable with the outgassing oxide. These stacks gave an improvement of the J_0e values with a factor of 6–9 for emitters with low surface concentration comparing to single SiN_x layer.

中文翻译：

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用于磷扩散硅太阳能电池发射器钝化的超薄等离子体氧化物

已经研究了磷扩散发射器上的不同钝化层。不同沉积温度下的氮化硅 (SiN _x ) 单层、“脱气”氧化硅堆叠（在脱气过程中在环境空气中移入/移出炉子期间生长）和超薄 SiO _x层之间的比较已经研究了通过覆盖有 SiN _x层的等离子体氧化形成的。在不同沉积温度下优化等离子体增强化学气相沉积 (PECVD) SiN _x显示出良好的钝化质量，具体取决于氢含量。在工艺气流中不使用硅源的 PECVD 工具的等离子体氧化工艺是形成薄 SiO 的明显选择_x因为它允许在同一在线 PECVD 工具中以一系列沉积工艺形成 SiO _x /SiN _x叠层。发现这种超薄 SiO _x层不仅在快速烧制过程后改善了表面钝化，而且还保持了 SiN _x优异的抗反射涂层 (ARC) 性能。低发射极饱和电流密度J_0电子对于表面电阻率为 161 Ω/sq 的发射器，平面电阻值为 15 fA/cm ²，纹理表面为24 fA/cm ^{2 值}，在 850 °C 下烧制后已达到，这与除气氧化物相当。这些堆栈改进了J_0电子与单个 SiN _x层相比，具有低表面浓度的发射器的系数为 6-9 。