多孔隙二氧化矽製備與電漿處理之研究

Preparation and Plasma Treatment of Porous Silica Thin Film

李益維(I-Wei Li)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300432

摘要

摘要
多孔隙二氧化矽是目前極具潛力之低介電常數材料。但是，其有著製程繁瑣及水氣吸附的問題，要與目前半導體製程做整合有其困難。本研究之第一部份利用溶膠凝膠法製備多孔隙二氧化矽薄膜，探討溶液配製、老化時間、表面改質以及退火處理等參數對薄膜性質之影響。發現在溶膠凝膠溶液配製部分，水的配比影響溶液pH值甚大；加入鹼液（NH4OH）濃度及溶膠溶液之溫度，對於膠化時間有一定之影響；老化時間長有助於孔洞生成，但老化時間過長使大孔洞產生，亦會造成後續退火製程時，薄膜因孔洞崩塌而變的較緻密。加入TMCS做薄膜表面改質確實有助於降低水氣吸附，亦可防止退火製程中孔洞的崩塌。除此之外，亦發現利用電漿反應器以真空退火方式取代傳統爐管退火製程，確實能有效縮短製程時間。本研究之第二部份則探討電漿處理對多孔隙二氧化矽膜材性質之影響，發現通入氣體（CF4、H2、N2）的不同確實對膜材在水氣吸附及表面結構上有不同程度的影響。其中，膜材經單一氣體電漿處理後，並無法降低膜材之介電常數及漏電流，而膜材經混合氣體電漿處理後，發現以適當配比之CF4/H2電漿在室溫下處理多孔隙二氧化矽確實可降低膜材之介電常數及漏電流。

關鍵字

水氣吸附 ； 電漿處理 ； 溶膠凝膠法 ； 低介電材料 ； 多孔隙二氧化矽 ； 介電常數

並列摘要

Abstract
Porous silica is one of the popular low-k materials, because it has lower dielectric and better thermal stability. However, porous silica has some issues regarding to complicated procedures and moisture uptake, therefore, compatibility of the film with IC processing is difficult. In this study, we preperated porous silica thin film by Sol-Gel method. The effects of control parameters, such as solution preparation, aging time, surface modification and annealing process, on the film properties were first studied. Then we investigated that effect of plasma treatment on properties of porous silica thin film. The results showed that the surface topography and the moisture uptake of film would vary with different plasma treatments. One of the with CF4/H2 plasma treatments could decrease not only dielectric constant but also leakage current. Furthermore, process time can be reduced by employing vacuum annealing to the film.

並列關鍵字

plasma treatment ； Sol-Gel method ； dielectric constant ； porous silica ； low-k material ； moisture uptake

參考文獻

NDL（國家奈米元件實驗室）, "半導體積體電路製程介紹（光碟版）" (2001)

Alayo M. I., I. Pereyra, W. L. Scopel and M. C. A. Fantini "On the nitrogen and oxygen incorporation in plasma-enhanced chemical vapor deposition (PECVD) SiOxNy films" Thin Solid Films 402 (2002) 154

Baskaran S., J. Liu, K. Domansky, N. Kohler, X. Li, C. Coyle, G. E. Fryxell, S. Thevuthasan and R. E. Williford, " Low Dielectric Constant Mesoporous Silica Films Through Molecularly Templated Synthesis" Advanced Materials 12 (2000) 291

Chang T. C., P. T. Liu, F. Y. Shih and S. M. Szea, "Effects of Hydrogen on Electrical and Chemical Properties of Low-k Hydrogen Silsesquioxane as an Intermetal Dielectric for Nonetchback Processes" Electrochemical and Solid-State Letters 2 (1999) 390

Chang, T. C., P. T. Liu, Y. S. Mor, S. M. Sze, Y. L. Yang, M. S. Feng, F. M. Pan, B. T. Dai, and C. Y. Chang, "The Novel Improvement of Low Dielectric Constant Methylsilsesquioxane by N2O Plasma Treatment" Journal of The Electrochemical Society 146 (1999) 3802