單晶矽太陽能電池中，其背面會鍍上鈍化介電層降低載子複合機率，而為了將電極與矽基板接觸將所生成的載子導出，所以要將鈍化介電層圖案化開孔。目前用來將介電層圖案化的技術有噴印保護層、噴印蝕刻以及雷射消融法，但是噴印保護層的製程繁瑣，且會有殘留物的問題，而雷射消融法則是會對晶圓表面造成缺陷，對效率都有影響。為了減少成本，縮減繁瑣的製程，雷射背電極燒結法(LFC, Laser Fired Contact)是近年來常被運用在太陽能電池製程的一種方式。雷射背電極燒結法整合了背面鈍化層開孔以及鋁膠燒結的製程，雖然縮短了製程，省下許多時間，但雷射背電極燒結法和雷射消融一樣，會使晶圓表面形成缺陷，對效率產生影響。
本研究利用噴塗的方式將霧化的蝕刻液噴在已鍍上鈍化層的晶圓表面，此蝕刻液為氫氟酸，將鈍化層依照遮罩上的圖案蝕刻開孔。這種方法不會對晶圓表面造成傷害，而且也縮短了噴印保護層的製程，節省許多製程成本。利用噴塗的方式我們可以改變氣流和遮蔽罩大小，進而控制開孔大小。而僅利用氫氟酸蝕刻在基板表面會往外攤開，使開孔周圍有一圈鈍化層厚度漸層，使開孔形貌不佳，本實驗在氫氟酸蝕刻液內添加磷酸，增加蝕刻液的黏度，讓蝕刻液在基板表面可以聚集，不會往外攤開，造成鈍化層厚度漸層，得到較佳的開孔形貌。本實驗利用磷酸比10%氫氟酸=1:10作為蝕刻液，可以將氧化鋁和氮化矽噴塗蝕刻，且孔洞大小與遮罩孔洞大小誤差在10%以內，且厚度漸層小於10μm。

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