Structural, electronic, and luminescence investigation of strain‐relaxation induced electrical conductivity type conversion in GeSi/Si heterostructures
Structural, electronic, and luminescence investigation of strain‐relaxation induced electrical conductivity type conversion in GeSi/Si heterostructures
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GeSi/Si 异质结构中应变弛豫诱导的导电类型转换的结构、电子和发光研究
DOI：
10.1063/1.363200
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发表时间：
1996
影响因子：
3.2
通讯作者：
E. Fitzgerald
中科院分区：
文献类型：
--
作者：
P. Grillot;S. Ringel;J. Michel;E. Fitzgerald
应变弛豫的，成分梯度Ge0.3Si0.7/Si异质结构生长的双真空化学气相沉积在650 °C下显示出一致的变化，从p型到n型导电性的快速热退火（RTA）温度在700-850 °C范围内的函数。横截面透射电子显微镜、扩展电阻和电子束感应电流（EBIC）的研究排除了位错本身作为这种类型转换的可能来源，通过证明2×1014 cm−3的空间不变空穴浓度与位错密度无关，位错密度从渐变区的108 cm−2下降到30% Ge帽层的7×105 cm−2。为了确定类型转换的来源，对650 °C生长和退火的样品进行了系统的研究，并进行了深能级瞬态光谱（DLTS），光致发光（PL）和电容温度（C-T）测量。对生长样品的DLTS测量揭示了一个复杂的深度光谱。
Strain‐relaxed, compositionally graded Ge0.3Si0.7/Si heterostructures grown by ultrahigh vacuum chemical vapor deposition at 650 °C are shown to display a consistent change from p‐type to n‐type conductivity as a function of rapid thermal annealing (RTA) temperature in the range 700–850 °C. Cross‐sectional transmission electron microscopy, spreading resistance, and electron beam induced current (EBIC) studies eliminate the dislocations themselves as a possible source of this type conversion, by demonstrating that the spatially invariant hole concentration of 2×1014 cm−3 is not correlated to the dislocation density, which decreases from ∼108 cm−2 in the graded region to 7×105 cm−2 in the 30% Ge cap. To identify the source of type conversion, a systematic investigation was performed on 650 °C as‐grown and annealed samples with deep‐level transient spectroscopy (DLTS), photoluminescence (PL) and capacitance–temperature (C–T) measurements. DLTS measurements on as‐grown samples reveal a complex spectrum of dee...