銅鎂接線與SiLK在多層金屬上的整合與電遷移可靠度提昇之研究

Abstract

銅鎂膜比銅對介電層的附著力佳，常壓爐管使銅產生氧化，而真空爐管真空度高，幾乎不會使金屬發生氧化。銅鎂膜比銅較能有效抵抗銅的擴散，退火後金屬的電阻率下降，另外退火後銅的結晶性也變好。真空爐管退火後，銅比銅鎂膜來的粗糙。在電遷移量測方面，以Oxide當介電材料的試片比SiLK有較佳的抗電遷移能力，銅鎂膜較銅有較佳的抗電遷移能力。金屬斷路的地方並非寬窄不一的接點，顯示熱遷移效應並不明顯。SiLK取代氧化層可使介電值下降、時間延遲減少等優點，不過也會多出一條漏電流路徑，此路徑是SiLK及氧化層的界面處，也可觀察出SiLK的非等向性現象。

The adhesion between dielectric material and Cu(Mg) is larger than Cu. Cu or Cu(Mg) will oxidize in air furnace, but won’t oxidize in vacuum furnace. Cu(Mg) can resist metal diffuse to oxide. After annealing, the resistivity of Cu or Cu(Mg) decreases and crystallinity increases. Oxide as a dielectric material has better EMD resistance than SiLK because of the higher Young’s Modulus, strength and thermal conductivity. Cu(Mg) has better EMD resistance than Cu because of the higher adhesion with dielectric material. Thermomigration is not appearing in this thesis. SiLK as a dielectric material can decrease RC time delay, but creates a new leakage current path; this path is the interface between SiLK and oxide. Anisotropic of SiLK is also observed.