太陽能電池之結晶矽與不同陶瓷坩鍋材料接合

Abstract

本研究『太陽能電池之結晶矽與不同陶瓷坩鍋材料接合(Silicon Contacts with Various Ceramic Crucibles for Solar Cell Applications)』是研究不同陶瓷坩堝與矽單晶片之間的介面反應及矽單晶片缺陷分析。本研究探討的陶瓷坩堝材料有SiO2、Al2O3、ZrO2及SiC，並與矽單晶片於1450℃/0.5h 接合反應，將利用掃瞄式電子顯微鏡（scanning electron microscopy, SEM）及穿透式電子顯微鏡(transmission electron microscopy, TEM)進行接合後的物性分析，並分別利用傅利葉轉換紅外光譜（Fourier transform infrared spectroscopy）及四點探針電阻量測儀(Four Point Sheet Resistance Meter)量測矽單晶片殘留氧濃度及阻值變化。Si與不同的陶瓷坩堝材料接合後，發現O都會往Si的方向擴散，使得接面中的Si產生差排，當中Si與SiO2接合後，除了差排堆積以外，還有裂痕的生成。Si與不同陶瓷坩堝材料接合後皆無介面反應相生成，除了與ZrO2接合後介面處會生成Y2Si2O7及ZrSi2反應相。在矽與氧化物陶瓷接合後的氧濃度及阻值的分析中，矽單晶介面處的氧濃度及阻值皆隨著遠離介面處而有降低的趨勢。實驗結果中以Al2O3為坩堝材料之試片中的生成缺陷與氧濃度分布比以SiO2為坩堝材料之試片結果理想，認為此種材料適合用於Si長晶的坩堝材料。

The research, Silicon Contacts with Various Ceramic Crucibles for Solar Cell Applications, focuses on the interfacial reaction between silicon wafer and various ceramic crucibles, such as SiO2, Al2O3, ZrO2, and SiC, after joining at 1450℃/0.5h in Ar. Analysis of physical properties after joining will rely on scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS). The residual oxygen concentration and resistance change of silicon crystal were measured by Fourier transform infrared spectroscopy (FTIR) and four point probe resistance measurement. After joining, the oxygen element from various ceramic crucibles will diffuse toward the silicon side and result in the dislocation formation at the surface of Si. In the Si/SiO2 joint, the dislocation piled up and crack appeared at the interface. There are no reactional phases at the interface between Si/various ceramic crucibles. Excepting the Si/ZrO2 joint, two phases, Y2Si2O7 and ZrSi2, will generate at the interface. The residual oxygen concentration and resistivity of the silicon are higher near the interface and both decrease gradually with increasing of the distance from the interface to the interior of Si. Summarily, the Al2O3 and ZrO2 ceramic crucibles are comparable to SiO2 crucible according to the residual oxygen and resistivity results. Among these crucibles, the Al2O3 has low dislocation distribution in the silicon than that of SiO2.