Fabrication of the Textures as Anti-Reflection Layer on the Silicon Wafer

[[abstract]]本研究中，使用濕式非等相性蝕刻於單面拋光之矽晶圓製作金字塔結構(pyramid textures)。由於反應進行時會於矽晶片表面釋放出氫氣，所以通常會於溶液中加入異丙醇(Isopropyl Alcohol, IPA)來降低氣泡所帶來的影響。 矽晶圓蝕刻製程參數包含：1.蝕刻溫度、2.KOH與IPA的濃度(或TMAH和IPA的濃度)、3.蝕刻時間與4.有無酸蝕刻。而本實驗使用HF、HNO3及CH3COOH作為酸性的等相性蝕刻液，使矽晶片產生缺陷以利之後使用非等相性蝕刻；再藉由適當的蝕刻製程參數，可產生高密度且大小相近的金字塔結構。實驗結果顯示，當矽晶圓經過酸蝕刻後，可縮短在低濃度的KOH與IPA(或低濃度的TMAH和IPA)粗化時間，可得到大小更相近的金字塔結構。在有酸蝕刻、濃度3%KOH與5%IPA、溫度80℃、蝕刻時間10分鐘，可產生最小的金字塔結構約2μm~4μm，在300nm~1000nm不同波長的反射率最低約為10%。[[abstract]]In this study, the pyramid textures on single polishing silicon wafer are fabricated by anisotropic wet etching. Isopropyl Alcohol (IPA) is often added to the solution to reduce the effect of the bubbles caused by hydrogen released form the silicon surfaces during reaction. These recipes of etching process on the silicon wafer include: 1.Etching temperature, 2. the concentration of KOH and IPA (or the concentration of TMAH and IPA), 3. Etching time and, 4.With or without acidic solution.In this study,the acidic solution of HF、HNO3 and CH3COOH as isotropic etching are used for causing defectson silicon wafer in order to facilitate the anisotropic etching silicon wafer had defects. By using appropriate etching process parameters can be fabricated the pyramid textures with high density and similar size. The results showed that after the acid etching, the concentration of 3% KOH and 5% IPA, temperature 80℃ and etching time of 10 minutes, the pyramid textures about 2μm~4μm can be fabricated on the silicon wafer. The lowest reflectance of the pyramid textures on the silicon wafer which were measured from 300nm to 1000nm is about 10%