鈦或氮化鈦底層與氧成分對金屬化製程之氮化鈦結構與性質的影響

Abstract

本實驗中探討預鍍鈦及氮化鈦對氮化鈦薄膜結構與性質的影響，並嘗試改變氧流量以探討氧成分對化鈦性質與結構的關係。實驗發現當於傳統濺鍍（亦稱無準直器濺鍍：uncollimated sputtering）、低濺鍍功率、低基材溫度時將氮化鈦具有〈111〉優選方向；於準直器濺鍍（collimated sputtering）、高濺鍍功率，高基材溫度則有助於降低氮化鈦薄膜；而於低基材溫度沉積之鈦薄膜具有＜0002＞優選方面，以此預鍍的鈦底層亦有助於氮化鈦往〈111〉成長。而根據上述結果，本實驗中成功發展一新穎的”兩階段氮化鈦沉積製程”(2-step TiN deposition process)，亦即在氮化鈦薄膜底下預鍍一上層〈111〉優選方向的氮化鈦（約100∼100A）作為seed layer，此製程得到的氮化鈦具有低電阻率(58.23u m-cm)、高〈111〉優選方向之氮化鈦薄膜，而此製程亦具有高沉積速率及高圖形底部覆蓋率(bottom step coverage)的優點，因此適用於深次0.25微米金屬化製程中。最後，本實驗亦發現增加氧含量時除了使氮化鈦薄膜趨於非晶質、增加電阻率以外，亦會提高漏電流值。

This study investigated the effect of predeposited Ti or TiN on TiN structure and properties. The relationship was investigated betweeen oxygen content and TiN properties and structure by changing oxygen flow. The TiN film has the 〈111〉 highly preferred orientation when the sputtering conditions are set at uncollimated sputtering, low sputtering power, and low substrate temperature. And it has a lower film resistivity when the sputtering conditions are set at collimated sputtering, high sputtering power, and high substrate temperature. TiN film will grow along 〈111〉 when one Ti underlayer with 〈0002〉preferred orientation was predeposited. Finally, one novel "2-step TiN deposition process" was successfully developed to grow the TiN film with a high deposition rate, low resistivity (58.23u Ω-cm), 〈111〉 highly preferred orientation, and high bottom step coverage by predepositing one underlayer (about 100A∼200A) as a seed layer. It is one novel and excellent process which can be applied to sub-quatrer micron metallization. The TiN film would tend to be amorphous, and the increase resistivity and leakage current increased with oxygen content.