摘 要 本實驗是使用IC微影製程的方式，在矽晶圓上製作出內連線引洞（Via）的結構，利用微波電漿化學氣相沉積系統（Microwave plasma chemical vapor deposition, MPCVD）在引洞結構中成長奈米碳管，來控制奈米碳管的定位成長，並且達到以奈米碳管來取代金屬內連線的目的。而在製作內連線引洞結構時，分別設計在相同範圍面積下，有單一引洞結構與陣列引洞結構且使用兩種不同金屬鉭（Ta）與鈦（Ti）當作下電極，最後沉積上電極金屬Ta與奈米碳管接觸完成二極體元件。再配合掃描式電子顯微鏡（SEM）、拉曼光譜儀（Raman spectroscopy）和I-V量測系統，分別探討在不同製程參數下，奈米碳管的形態與石墨化程度對其二極體元件電性的影響，並且比較兩種不同下電極金屬（Ta與Ti）在相同面積下，單一引洞與陣列引洞結構對二極體元件其電性的差異。 由本實驗的結果可以發現，奈米碳管的直徑隨著前處理電漿功率與基板溫度的增加而逐漸減小。而隨著成長電漿功率與基板溫度的增加，所成長奈米碳管的石墨化程度較好，元件的電阻值也較低。在相同面積下，陣列引洞結構之元件的電阻值，比單一引洞結構之元件的電阻值還小，且在相同製程參數下，以Ti為二極體元件的下電極時，其電阻值比Ta為下電極時所量測到的電阻值還小，因此在本實驗中以Ti為下電極時，基板溫度為650 ℃、前處理電漿功率為1200 W、成長電漿功率為800 W、甲烷氣體流量比例為20% 時，所成長的奈米碳管其石墨化程度最好（約為50%），並且量測到其二極體元件的電阻值也是最低（約為60 Ω）。 Abstract This research is using microwave plasma chemical vapor deposition（MPCVD）to grow carbon nanotubes（CNTs）. We use integrated-circuit（IC） photolithography to manufacture the structure of interconnect via in silicon wafer to control the growth of vertically aligned carbon nanotubes （CNTs） and achieve replacing the metal in the via by CNTs. We design a single-via and array-via in the same region with two different metals（Ta and Ti） as bottom electrode. We, finally, deposit Ta to connect with CNTs to accomplish CNT diode structure and make use of SEM, Raman spectroscopy, and I-V system to analysis diode structure. We discuss the effect of process parameters on the properties and the diode resistances of CNTs in single and array via, and then compare with Ta and Ti of bottom electrode of conductive performance. We find out that multi-wall carbon nanotube（MWNT） diameter decreases with increasing pretreatment plasma power and substrate temperature; the degree of graphitization of MWNTs increases with growth plasma power and substrate temperature. Consequently, the diode resistance of MWNTs in both single and array vias decreases with increasing MWNT graphitization. However, in the same via region, the MWNT diode resistances of the array vias are lower than those of the single vias; the MWNT diode resistances on the bottom electrode of Ti are lower than those on the bottom electrode of Ta. So, at PP: 1200 W, PG: 800 W, Temp. : 650 ℃, and CH4 flow ratio: 30%, we measure the best degree of graphitization (50%) and the lowest MWNT diode resistance (60 Ω).
