在絕緣體上單晶鍺薄膜上製作自旋載子注入與偵測元件與其特性之研究

Abstract

本論文中使用Smart cut技術自行製作絕緣體上高品質單晶鍺薄膜基板，該方法是鍺晶圓以氫離子佈植後，利用表面活化將玻璃基板以及經過離子佈植之鍺晶圓接合，最後利用退火的方式將鍺薄膜轉移到玻璃基板上，完成製作絕緣體上高品質單晶鍺薄膜基板。並利用此基板來製作自旋載子注入與偵測之元件，該方法為利用一四端結構鐵磁性金屬氧化物半導體之結構，將自旋載子從鐵磁性金屬注入至半導體鍺中，且利用漢勒效應來探討其自旋載子之自旋特性。在論文中，詳述了製程的方法及參數，並且探討元件電性的基本特性，同時我們以霍爾量測的方式來評估絕緣體上單晶鍺薄膜基板的電阻率及載子遷移率，進而探討離子佈植對鍺薄膜之影響。由於我們所使用的四端元件可簡單偵測到自旋載子，因此非常適合用來研究自旋載子在半導體中的特性。而在本論文中，我們順利在室溫下量測到N-type及P-type元件之漢勒效應，並且在室溫下得到較長的載子之Spin lifetime(N-type : 160 ps、P-type : 33 ps)。

In this thesis, we success in using Smart CutTM to fabricate high quality germanium thin film on insulator(GeOI) substrate. We use proton ion implantation following with direct bonding on the glass substrate. And use thermal annealing to cut the thin film from Ge substrate. Then we used four-terminal structure to fabricate the device of spin injection and detection. Using the four-terminal structure device with ferromagnetic metal-oxide- semiconductor structure to inject spin carriers and using Hanle effect to detect the spin signal. In this thesis, I will mention fabrication process parameters and the method of measurement. In the last part I will discuss the basic characterization of four-terminal device. In the end, we got the carrier mobility in germanium thin film by hall effect. The proposed structure can be simply measured the spin signal, therefore, it can be used to study the characteristics of spin polarized carriers in semiconductors. We success in measuring the Hanle effect signal and obtain higher Spin lifetime at room temperature (160 ps for N-type and 33 ps for P-type).