碲及鎂參雜磷化銦鋁材料之缺陷研究

Abstract

本研究係利用深能階暫態量測法研究以有機金屬氣相磊晶法成長之碲及鎂參雜磷化銦鋁材料中存在之深能階缺陷。在碲參雜磷化銦鋁材料的研究方面，總共研究了五種不同五三比的材料，在所有不同五三比的材料中皆存在一個深能階缺陷，其活化能為0.4eV。其次以五三比120來成長不同參雜濃度的磷化銦鋁材料，發現此缺陷隨碲的參雜濃度上升而上升，並且在樣品內呈現均勻分布的情況，因此研判此缺陷為一與參雜相關的塊材缺陷。當五三比降到80以下時，另外發現了一個活化能為0.69eV的深能階缺陷，它的濃度隨五三比下降而上升，並在樣品內均勻分布，由磊晶的過程研判此缺陷可能是由磷空缺所造成。在鎂參雜磷化銦鋁的研究方面，發現存在三個深能階缺陷(M1、M2及E0)，其活化能分別為0.26eV、0.55eV及1.06eV。其中M1及M2的濃度亦發現隨參雜濃度增加有上升的趨勢，所以M1及M2亦是與參雜相關的缺陷。另外由於E0的活化能相當高，可能是再結合中心所形成的缺陷。在照光研究的部分，M1的濃度在照光時有明顯的增加，而M2則無，這是因為照光時產生電子電洞對所導致。

Deep level transient spectroscopy (DLTS) technique was used to study the deep level defects in Te- and Mg-doped AlInP grown by metal-organic chemical-vapor deposition (MOCVD). Samples of Te-doped AlInP with different V/III mole ratios of 160、120、80、60 and 40 were prepared. Two trapping centers were found in Te-doped AlInP, one (T1) existing in all kinds of samples with activation energy of 0.4eV and the other one (T2) with activation energy of 0.69eV existing in samples with V/III mole ratio lower than 120. The concentration of T1 is increased with Te-dopant concentration and is uniformly distributed with depth in Te-doped AlInP, so it’s referred to dopant-related defect. T2 exists only in samples with V/III mole ratios of 80、60 and 40. Its concentration is increased with decreasing the V/III mole ratio. Phosphorus vacancy is thought of the main soure of trapping center T2. The study of Mg-doped AlInP revealed that there are three deep level defects (M1、M2 and E0 with activation energy of 0.26eV、0.55eV and 1.06eV respectively) existing in Mg-doped AlInP. Concentrations of both M1 and M2 are increased with Mg-dopant concentration, and they were also regarded as dopant-related defects. The fact of E0 with higher activation energy (1.06eV) suggests that one or more recombination centers exist in Mg-doped AlInP. The concentration of M1 is markedly increased under illumination because of generating electron-hole pairs, and that of M2 keeps unchangeable.