銅化學氣相沈積基本特性及基板電漿前處理之研究

Abstract

本論文探討銅化學氣相沈積的基本特性、基板的（Ar、H2）電漿前處理效應以及化學氣相沈積銅之填洞能力。吾人以一種液態有機金屬複合體Cu(hfac)TMVS+2.4%TMVS當作先驅物，進行銅化學氣相沈積，探討銅化學氣相沈積的活化能，以及銅膜的電阻率、表面型態等性質。在基板的電漿前處理部分，吾人分別以利用物理性的氬氣電漿(Ar plasma)及化學性的氫氣電漿(H2 plasma)對TaN基板作前處理，探討其對成核及銅膜特性的影響。在電漿處理過的基板上，銅之成核數大量增加，而且所沈積之銅膜具有較高的(111)/(200)晶向比、晶粒較小形狀較有規則、以及表面較平整等特性。再者，吾人亦探討製程參數對填洞能力的影響，實驗結果顯示在低壓（60mtorr）、低溫（120~160oC）、高先驅物流量（0.4ml/min）條件下，化學氣相銅沈積具有優越的填洞能力，可對高寬比為9.1的0.11微米管洞，完成無空隙之管洞填充。

This study investigates the basic characteristics of copper chemical vapor deposition (Cu CVD), effects of substrate pretreatment by Ar and H2 plasma, and the via-filling capability of Cu CVD. A liquid metalorganic compound of Cu(hfac)TMVS+2.4%TMVS was used as precursor for the study of Cu CVD regarding the growth rate, electrical resistivity, surface morphology, and crystallinity of Cu films at a substrate temperature of 120 to 240oC. Effects of TaN substrate pretreatment by Ar and H2 plasma were investigated with respect to Cu nucleation and Cu film properties. On the plasma treated substrate, drastic increase of Cu nucleation site was observed, and the Cu films deposited contain smaller grains, smoother surface, and higher ratio of Cu(111)/Cu(200) preferred orientation. Moreover, effects of process parameters on via-filling capability were investigated. It is found that the conditions of low pressure, low temperatures, and high precursor flow rate favor the via-filling. It turns out, in this study, that Cu CVD at a deposition pressure of 60mtorr, a substrate temperatures of 120 to 160oC, and a precursor flow rate of 0.4ml/min is capable of void free filling on the vias of 0.11μm size and 9.1 aspect ratio.