上閘極單壁奈米碳管場效電晶體之研究

楊杰舜(Shun Yang)

指導教授 ： 戴念華

國立清華大學/工學院/材料科學工程學系/碩士(2007年)

摘要

通常單壁奈米碳管成長方向為垂直金屬催化劑表面，因此吾人在催化劑表面上再濺鍍一層鋁層，而此一鋁膜也有效地抑制單壁奈米碳管的垂直成長。另一方面，控制區塊間距和區塊的形狀兩種關鍵參數，能成長出單根跨接碳管的單元。
對已經完成跨接的單元進行電流-電壓曲線量測，可以確認跨接碳管的電學性質。有些單元表現線性的電流-電壓曲線，為金屬性的跨接單壁奈米碳管；而其他單元則是顯示非線性的曲線，在偏壓為零附近有一無電流區域。藉由結合原處成長單壁奈米碳管方式和黃光微影技術，吾人製作出可單一操作的上閘極單壁奈米碳管場效電晶體，同時也發現在不同能隙大小的單壁奈米碳管通道之元件，可以表現出廣義p型及雙極性場效電晶體兩種不一樣的性質。總而言之，成功操作上閘極結構為核心的元件，使得單壁奈米碳管可以更接近積體電路的運用。

關鍵字

單壁奈米碳管 ； 場效電晶體 ； 跨接

並列摘要

Generally single wall carbon nanotubes (SWNTs) grow in the vertical direction on the catalytic metal plane. Therefore we deposited an Al layer of 10 nm on the catalytic layer by sputtering. The Al layer plays the role of a barrier to prevent vertical growth of the SWNTs effectively. In addition, the size of the gap between the pads and the sharp of the pads are the key parameters for determining the chemical vapor deposition (CVD) growth duration for successfully bridging the pads by individual SWNT.
To determine the electric properties of the SWNTs contacts, detailed current-voltage (I-V) measurements were performed on sample with the different SWNT connections. Some I-V curves are linear, suggesting metallic behavior; others exhibit nonlinear and a low conductance region develops around V=0. By combining the advantages of in-situ carbon nanotube growth technology and the lithography technology, we have realized the top-gate single wall nanotubes field effect transistors (SWNT-FETs) with individual device operation. We have succeeded in observing ambipolar and generalized p-type transistor operation in variable band gap semiconducting SWNT channels. In summary, the results indicates that the top-gate structure can be operated and demonstrate the potential of SWNT for the future complementary electronic.

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