在P型多孔矽形成中的光鈍化效應

Light-Passivation Effect on P-type Porous Formation

張繼元(Ji-yuan Jang)

指導教授 ： 李天錫

國立中央大學/工學院/機械工程學系/碩士(2013年)

摘要

多孔矽的發現始於1956年，在Uhlir進行矽晶圓的電化學拋光時，無意間發現晶圓上出現一層黑色薄膜，此薄膜即為多孔矽。而後數十年來有關多孔矽的研究日益廣泛，在各大領域諸如微機電製程、半導體元件、太陽能電池、生醫工程等等皆有活躍的應用。
一般而言，佈植硼(3A族)的P型矽晶圓上具備了電子電洞對，能夠正常地用電化學蝕刻的方式製作出多孔矽；而佈植砷(5A族)的N型矽晶圓因為只具備電子，必須予以紫外光照方能產生電洞，讓電子間接躍遷產生蝕刻反應，才可製作出N型矽晶圓上的多孔矽結構。因此，從事N型矽晶圓之光電化學蝕刻的研究以及相關文獻不勝枚舉，但一般學者卻很少研究有關P型矽晶圓的光電化學蝕刻。
本研究為在P型矽晶圓上進行電化學蝕刻時，輔以不同功率輸出的雷射光照，觀察其光照能量對於蝕刻速率的影響。研究發現，在能量越強的雷射光照射下，越難進行蝕刻反應。最後再以阿瑞尼斯方程式分析其活化能，推導出不同光功率與蝕刻速率、活化能之間的關係式。此技術可取代在微機電技術的顯影製程以及一般半導體蝕刻製程中塗佈光阻與移除光阻的步驟，除可以縮短製程時間與降低成本外，還可將元件做得更小，達到奈米的等級。

關鍵字

晶圓 ； 多孔矽 ； 光鈍化

並列摘要

Porous silicon was discovered in 1956, Uhlir accidentally discovered a black film layer on the wafer in electrochemical polishing on silicon wafers.The film is called porous silicon. After the decades,the researches on porous silicon increase widespreadly on different areas such as MEMS, semiconductor devices, solar cells, biomedical engineering, etc.
In general, the P-type silicon wafer of the implantation of boron (III A)with the electron-hole pairs can normally use electrochemical etching method to produce porous silicon;the N-type silicon of the implantation of arsenic (V A)with only electron,it must be use UV irradiation to let the wafer produce hole,and the electron can conduct indirect transitions produce,finally the N-type silicon wafer can produce etching reaction to make the porous silicon structure in etching process. Thus,the photoelectrochemical etching studies and literature on the N-type silicon wafers are numerous, but most scholars rarely reasearch the photoelectrochemical etching of the P-type silicon wafer.
This study is reasearching the electrochemical etching for the P-type silicon wafer combined with different power output of the laser light.The etching rate is observed for the different light energy. This study found that the energy of laser light irradiation is stronger,the etching reaction is harder to be advanced. Finally, in order to analyze the activation energy, this study use Arrhenius equation deduced the relation between the different light power, the etching rate, and the activation energy. This technology can replace the photoresist coating and removing steps of the lithography technology on MEMS and the semiconductor etching process, in addition to the process time can be shortened and reduce costs, but also the size becomes smaller as small as nanometer.

並列關鍵字

wafer ； porous silicon ； Light-Passivation

參考文獻

46. 黃俊達，卓其何，「多孔矽/n-Si結構的光電特性探討」 ，科學與工程技術期刊，第四卷，第三期，2008.

1. X. Hong, “Introduction to semiconductor manufacturing technology”, Pearson Education , Issue 6, 92, (2000).

2. A. Uhlir, “Electrolytic shaping of germanium and silicon”, Bell System Tech. J., 35, 333, (1956).

3. D. R Turner, “Electropolishing silicon in hydrofluoric acid solutions”, J. Electrochem. Soc.105,653, 92, (1958).

4. T. Osaka, K. Ogasawara, and S. Nakahara,“Classification of the pore structure of n-type silicon and its microstructure”,J. Electrochem. Soc.144,3226,(1994).