微波照射對晶圓電漿加強鍵合強度影響之研究

Study of the effect of Plasma-enhanced wafer bonding strength under microwave Irradiation

李任翔(Jen-Hsiang Li)

指導教授 ： 李天錫

國立中央大學/工學院/機械工程學系/碩士(2012年)

摘要

在半導體產業中，因絕緣體上矽材料(Silicon on Insulator ; SOI)發展解決了傳統塊材矽所面臨到的問題，而且提昇了固態元件的效率和降低能量損耗，而通常是利用智切法(Smart-Cut)來製作SOI 材料的方法，它的步驟如下：晶圓清洗、氫離子佈植、晶圓鍵合、退火以及化學機械研磨。在上述步驟中，晶圓鍵合的階段是需要將晶圓維持在高溫，使鍵合強度達1.5 J/m2才得以進行薄膜轉移，原因是為了避免晶圓在剝離後，矽薄膜無法附著在另一片晶圓上；然而此階段容易因高溫熱處理而帶來熱應力的問題，使得生產良率降低，且利用傳統加熱的方式通常需要很長一段時間，才能使晶圓達到高溫。而希望藉由氧離子電漿方式活化晶圓表面，並且以微波取代傳統加熱，使晶圓在低溫與短時間內到達高鍵合強度。
　　本研究目的在於晶圓經過了氧電漿活化後，鍵合強度對微波活化的影響：實驗是以相同氧電漿活化後的試片，施以不同微波功率與控制時間，再利用紅外光影像觀測微波後的晶圓對和裂縫開口法計算出鍵合強度。結果顯示，微波過後Si/Si、Si/Ox、Ox/Ox 三種晶圓對之鍵合強度在短時間與低溫可得到增強的效果，其中以Si/Ox 晶圓對在微波900W 20 分鐘後效果最為明顯。

關鍵字

微波 ； 晶圓鍵合

並列摘要

In the semiconductor industry, the development of silicon on insulator (SOI) solves the happened problems of conventional bulk silicon, and improves the efficiency of solid state devices and reduces the loss of energy. It is usually using Smart-Cut to produce SOI, and it need following steps: wafer cleaning, the hydrogen implantation, wafer bonding, anneal and chemical mechanical polishing. On the stage of wafer bonding, wafer bonding strength needs 1.5 J/m2 on high temperature, in order to layer transfer, because the silicon films can’t bond the other wafer after peeling off wafer. But it’s easy to happen on this stage, the thermal stress for high temperature heating procedure that reduces producing yield rate, and conventional heating usually needs a long time to obtain high bonding strength. So we uses oxygen plasma to activate wafer surface, and using microwave replaces conventional heating, wafer bonding pair obtains high bonding strength at lower temperature and shorter time.
　　This study is about the effect of microwave irradiation for bonding strength after wafers are activated by oxygen plasma. In the experiment, the test chips activated by some parameter of oxygen plasma use different microwave power and control time, and then use crack-opening method to measure bonding strength and infrared image topography. In experimental results, three bonding pairs of Si/Si, Si/Ox, and Ox/Ox, after using microwave irradiation, their bonding strength increase on lower temperature and shorter time. It is especially that the binding pair Si/Ox after using 900W microwave and twenty minutes, its effect is the most obvious.

並列關鍵字

wafer bonding ； microwave

參考文獻

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