| 摘要: | 本實驗使用傳統光學微影(Optical photolithography)的方式，利用I-line光學步進機系統進行曝光，接著顯影出我們設計好的圖案，經過蝕刻過程蝕刻出內連線引洞結構，在經過電漿前處理，使鎳薄膜催化劑轉為顆粒狀，最後利用低溫化學氣相沈積從引洞中成長出奈米碳管，且由奈米碳管取代金屬內連線，以達成本實驗之目的。在這之前我們會先以沒有圖案的金屬基板來成長奈米碳管，藉由調整實驗參數成長出垂直排列的奈米碳管，設定的參數包括: 鎳薄膜厚度，電漿前處理的參數；如: ICP power、Bias power、時間及氣體流量比例，以及LT-CVD的成長參數；如: 碳源比例、氣體總流量及壓力，並用掃描式電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)及拉曼散射分析來觀察參數對奈米碳管形態以及品質的影響，最後再將最佳的實驗參數應用在有引洞結構的基板，之後鍍上上電極金屬Ti，完成由奈米碳管做為垂直導線的二極體元件，再由I-V量測系統量其電性。 由本實驗的結果可以發現，隨著鎳薄膜厚度的減少，奈米碳管管徑逐漸減少。而經過電漿前處理後，成長出的奈米碳管管徑有明顯變小。氫電漿前處理比氨電漿前處理具有較強的蝕刻效果。進行電漿前處理中必頇要有Bias power的輔助，不然電漿中的陽離子沒有足夠的加速度蝕刻鎳薄膜成為顆粒狀。要在低碳源比例下成長出奈米碳管，並頇經過電漿前處理將鎳薄膜蝕刻成為較小的鎳顆粒。成長奈米碳管中的氣體流量會影響碳源是否有足夠時間解離並進入鎳顆粒當中。成長奈米碳管中過多的氫氣會造成鎳顆粒的蝕刻以及影響奈米碳管品質。本實驗中，鎳薄膜為1 nm在TiN金屬基板上，電漿前處理參數: ICP power為100 W、Bias power為50 W、壓力為100 mtorr、H2與Ar流量為100/20 sccm、基板溫度為400℃及前處理時間為3分鐘，成長奈米碳管參數:成長溫度550 ℃、壓力760 Torr、 ii Ar/H2/Are 流量為400/100/100 sccm及成長時間 15分鐘，所成長出的奈米碳管有較好的品質以及密度。而鎳薄膜為1 nm (南科)在TiN金屬基板上，電漿前處理參數(中山): ICP power為100 W、Bias power為100 W、壓力為20 mtorr、H2與N2流量為100/20 sccm、基板溫度為350℃及前處理時間為3分鐘，成長奈米碳管參數:成長溫度550 ℃、壓力760 Torr、 Ar/H2/Are 流量為485/15/100 sccm及成長時間 15分鐘，所成長出的奈米碳管，有較好的奈米碳管品質，管徑最小為8.4 nm，平均管徑約為11 nm。 This research is using low temperature chemical vapor deposition (LTCVD) to grow carbon nanotubes (CNTs) for interconnect application. We use integrated-circuit (IC) photolithography to manufacture the structure of interconnect via in silicon wafer, than development of hydrogen/ammonia plasma pretreatment for transforming Ni film into small and dense catalytic nanoparticles to growth of carbon nanotubes (CNTs) with nickel (Ni) catalyst on (TiN) layer by thermal CVD system with ethanol precursor. We design a single-via and array-via to grow carbon nanotubes (CNTs), finally, deposit Ti to connect with CNTs to accomplish CNT diode structure and make I-V system to analysis diode structure. Use diode structure before ,we were used of SEM, Raman spectroscopy and TEM system to analysis plasma pretreatment and CNT growth parameters on the blanket substrate. We find out that carbon nanofibers (CNFs) diameter increases with the catalyst thickness. The carbon nanotubes (CNTs) decreases with plasma pretreatment, H2 plasma has higher etching effect than NH3 plasma. Low plasma and bias power with proper hydrogen flow rate are essential to transform thin Ni film into small and dense nanoparticles by the plasma pretreatment. Small nickel particles require less carbon source for CNT growth. Dense carbon nanotubes (CNTs) were attained by the conditions : plasma pretreatment (NDL)─ ICP = 100 W, Bias = 50 W, Pressure = 100 mtorr, H2/Ar = 100/20 sccm, Temp.= 400 ℃, Time = 3 min.；CNT growth ─ Pressure = 760 torr, Ar/H2/Are = 400/100/100 sccm, Temp. = 550 ℃. Dense carbon nanotubes (CNTs) were attained by the conditions : plasma pretreatment (中山大學) ─ ICP = 100 W, Bias = 100 W, Pressure = 20 mtorr, H2/N2 = 100/20 sccm, Temp.= 350 ℃, Time = 3 min.；CNT growth ─ Pressure = 760 torr, Ar/H2/Are = 485/15/100 sccm, iv Temp. = 550 ℃. |
