整合光輔助電化學穿孔蝕刻與微電鑄技術應用於微金屬柱陣列之研製

Fabrication of metal micropillars array by integrating photo-assisted electrochemical etching through-holes and electroforming techniques

李明承(Ming-Cheng Li)

指導教授 ： 程金保 ； 楊啟榮

國立臺灣師範大學/科技學院/機電科技研究所/碩士(2006年)

摘要

本研究將整合光輔助電化學蝕刻(ECE)與?密電鑄技術，以開發高密??屬垂直結構陣?之製程技術。?用改變光照強?與電?密?等實驗條件，以電化學蝕刻達到矽晶圓高密?微穿孔的目的，再?用?密電鑄技術進?穿孔之?屬導體填充，如此可實現高密??屬垂直結構陣?。未?可應用於積體化探針陣?之製作，或?用晶圓內垂直導體而實現晶圓級堆疊封裝之目的。此技術開發有設備與製程成本低、可積體化生產、與半導體製程相容性高、批次生產與??高等特點。
基於上述，本研究利用自行開發之低成本電化學蝕刻(ECE)設備，順利測得相關製程之最佳參數。由實驗結果已驗證，在利用電化學蝕刻技術製作高深寬比微孔洞陣列方面，當蝕刻時間達到31.5小時，可得高深寬比之結構。所用之晶片為n-type (100)，其蝕刻液為2.5 wt.%之氫氟酸溶液，陽極放置矽晶片，陰極為白金，獲得之穿孔其邊長為40 mm，深寬比約為12.5，證明利用此技術已能局部取代乾式蝕刻之應用領域。在金屬柱電鑄方面，利用正負脈衝電流，使金屬柱陣列能順利成形，其金屬柱高度約500 mm，深寬比約為12.5。

關鍵字

微機電系統 ； 電化學蝕刻 ； 微電鑄技術

並列摘要

This research will integrate photo-assisted electrochemical etching (ECE) and electroforming techniques for fabricating high-density metal micropillars. This process is described as followed: high-density through holes in silicon are etched by photo-assisted electrochemical etching under various paramerers; then the through holes are fully filled by copper electroforming technique to form high-density metal micropillars. The deveploed technology will be promising for the application of integrated probe array and wafer-level package in the further.
Because of the above-mentioned, this research used the low-cost electrochemical etching (ECE) equipment developed by ourselves and got the best parameters of the related manufacture. The experiment result proved that the technology had been able to partially replace the dry etching technology. Using the ECE technology to fabricate high aspect of micro-pores array, we can get the structures of high aspect when the etching time reached 31.5 hours. Through-holes were formed by selective partial electropolishing in a 2.5 wt.% HF electrolytic solution, using an N-type, (100)-oriented Si wafer as an anode, and a Pt plate as a cathode. The obtained holes were square through-holes of 40 mm side length, with an aspect ratio of 12.5. Metal micropillars was made by electroforming technology with pulse and reverse current. The height of metal micropillars achieves 500 mm and the aspect ratio cab reach 12.5.

並列關鍵字

micro electro mechanical system ； electrochemical etching ； electroforming technology

參考文獻

2. M. D. B. Charlton, H. W. Lau, and G. J. Parker, "High aspect ratio photo-assisted electro-chemical etching of silicon and its application for the fabrication of quantum wires and photonic band structures", IEE Colloquium on Microengineering Applications in Optoelectronics, (1996) pp. 1-9.

3. A. Satoh, "Formation of through-holes on silicon wafer by optical excitation electropolishing method", Japanese Journal of Applied Physics, Vol. 39, (2000) pp. 378-386.

4. V. Lehmann and H. F?ll, "Formation mechanism and properties of electrochemically etched trenches in n-type silicon", Journal of the Electrochemical Society, Vol. 137, (1990) pp. 653-658.

5. V. Lehmann and U. Gr?ning, "The limits of macropore array fabrication", Thin Solid Films, Vol. 297, (1997) pp. 13-17.

6. V. Lehmann, "The physics of macropore formation in low-doped n-type silicon", Journal of the Electrochemical Society, Vol. 140, (1993) pp. 2836-2843.