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本文用4.2K光致发光研究了LEC GaAs的热感生缺陷.热退火时样品分别为无包封,包封或用一个未掺杂的SI-GaAs片覆盖.退火温度为650-850℃,退火在不同气氛下进行(真空,H_2,N_2,H_2+N_2或H_2+As_2). 与缺陷有关的发光带有1.443eV,1.409ev和0.67eV发光带.1.443eV发光带不仅在富Ga的GaAs中出现,而且在富As的热稳定性好的SI-GaAs晶体并经过850℃(在H_2中)热退火的样品中也观测到此发光带.这可能是在退火过程中促进反位缺陷GaAs的形成.1.443eV发光带与GaAs有关.GaAs晶体在H_2中退火后1.409eV峰很强,但在真空中退火末探测到此发光带.文中提出它可能是热退火时氢原子扩散到GaAs晶体中并与某些缺陷结合成络合物的新观点.
In this paper, the thermal induced defects of LEC GaAs were studied by 4.2K photoluminescence.The samples were unsealed, encapsulated or covered by an undoped SI-GaAs film respectively during annealing.The annealing temperature was 650-850 ℃, Annealing was performed in different atmospheres (vacuum, H_2, N_2, H_2 + N_2 or H_2 + As_2) .The flaw-related luminescent bands were 1.443eV, 1.409ev and 0.67eV.The luminescence bands of 1.43eV were not only observed in Ga- , And was also observed in samples rich in As-rich, thermally stable SI-GaAs crystals and thermally annealed at 850 ° C (in H 2), which may be due to the promotion of anti-phase defect GaAs during annealing .1.443eV luminescent band is related to GaAs. The 1.409eV peak of GaAs crystal annealed in H_2 is very strong, but this luminescent band is detected after annealing in vacuum. It is suggested that it may diffuse into GaAs crystal during thermal annealing And combined with certain defects into a new point of view of the complex.