以低壓有機金屬化學汽相沉積法成長磷化銦鎵與砷化鎵異質結構之研究

Abstract

本論文中以低壓有機金屬化學汽相沉積法(LP-MOCVD)研製磷化銦鎵與砷化鎵異質結構，以作為金屬半導體場效電晶體(MESFET)之應用。研究內容包含成長磷化銦鎵及砷化鎵異質結構的磊晶層、對不同成長條件所得磊晶層的特性分析。 在成長磷化銦鎵與砷化鎵磊晶層時，調變五族與三族的比例以得到最佳的低應變晶格匹配結構。同時，利用雙晶x光繞射定量分析超晶格磊晶層。光激光半高寬分析也用來印證我們的磊晶結構的優越特性。為了得到較好的磷化銦鎵與砷化鎵超晶格結構，適當的五族氣體切換扮演著一重要角色。事實上，磷化銦鎵與砷化鎵間的異質接面品質嚴重地受到一”trade-off”切換條件所影響。藉由氣體切換的最佳化，可在磷化銦鎵與砷化鎵之間得到較平坦的界面。

In this thesis, we have fabricated a new InGaP/GaAs heterostructure grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) for MESFET applications. The study includesd the epitaxial growth of the InGaP/GaAs heterostructure, structure and property characterization of epitaxial layers in different growth conditions. In the growth of InGaP and GaAs epi-layers, V/III-ratio was optimized to achieve the lattice-matched, strain free structure. Double crystal x-ray diffraction quantitatively studied the lattice mismatch of epitaxy. PL-FWHM data proved the superior properties of the epitaxial layer. To establish a better InGaP/GaAs heterostructure, the proper switching of group Ⅴ source (As and P) played a important role. The quality of the heterojunction between InGaP and GaAs was controlled carefully by a “trade-off” switching condition. Smooth interface between InGaP and GaAs was obtained due to the optimization of the switching conditions in this study.