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使用自动变温霍耳测试系统测定了减压 MOVPE外延生长的 Cδ掺杂 Alx Ga1-x As多层外延与pipi Alx Ga1-x As超晶格 .结果表明 ,以 TMAl为掺杂源的 Cδ掺杂 Alx Ga1-x As多层外延样品的二维空穴浓度可达到 1.1× 10 13 / cm2 ,比以 TMG为掺杂源的样品提高一个数量级 ,且其掺杂浓度对 Al摩尔分数的依赖程度远较使用 TMG为低 .实验还发现具有 10 15/ cm2二维空穴浓度的 Cδ掺杂 pipi Alx Ga1-x As超晶格的迁移率与具有 10 13 / cm2二维空穴浓度的 Cδ掺杂 Alx Ga1-x As多层外延的迁移率几乎没有差别 ,证实了 pipi Alx Ga1-x As超晶格中各δ掺杂层的电子云交叠大大减弱了电离杂质散射 ,使迁移率得到显著提高 .
The Cδ-doped AlxGa1-xAs multi-layer epitaxy and pipi AlxGa1-xAs superlattices were fabricated by MOVPE epitaxial growth using an automatic temperature-changing Hall effect test system. The results show that C δ -doped with TMAl as doping source The 2D hole density of the AlxGa1-xAs multilayered epitaxial samples can reach 1.1 × 10 13 / cm 2, which is an order of magnitude higher than that of the samples doped with TMG and the dependence of the doping concentration on the Al molar fraction is far Which is lower than that of TMG.It was also found that the mobility of Cδ-doped pipi AlxGa1-xAs superlattices with a two-dimensional hole density of 1015 / cm2 and the Cδ-doping with two-dimensional hole density of 1013 / cm2 The AlxGa1-xAs multilayer epitaxy has almost no difference in mobility, confirming that the electron cloud overlap of each δ-doped layer in the pipi Alx Ga1-x As superlattice greatly reduces ionized impurity scattering and significantly increases the mobility .