Thin anodic oxides formed on GaAs in aqueous solutions
Thin anodic oxides formed on GaAs in aqueous solutions
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水溶液中 GaAs 上形成的薄阳极氧化物
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
M. J. Graham
中科院分区：
文献类型：
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作者：
P. Schmuki;G. Sproule;J. Bardwell;Zhen;M. J. Graham
在水溶液（硼酸盐缓冲液，pH 8.4和0.3 M NH 4 H2 PO 4，pH 4.4）中在p-GaAs（100）上形成薄（0-250 A）阳极氧化物。通过X射线光电子能谱、二次离子质谱、椭圆偏振仪和电化学阻抗谱表征厚度、组成和电化学行为。在硼酸盐缓冲液中，氧化物生长导致两层结构，外层富含As 2 O3，离子转移主要受扩散控制。从膜厚度的电位依赖性，确定25 A/V的生长速率。由于在NH 4 H2 PO 4中形成Ga-磷酸盐前体层，薄膜在场控制下生长，这导致氧化物厚度和组成的时间依赖性。在准稳态条件下，获得了28 A/V的生长速率。在NH_4H_2PO_4中形成的薄膜，除了外层磷酸盐层外，在深度上具有相当均匀的组成，具有显著富集的Ga_2O_3，并且显示出比电荷转移电阻高40倍。
Thin (0–250 A) anodic oxides were formed on p‐GaAs (100) in aqueous solutions (borate buffer, pH 8.4 and 0.3 M NH4H2PO4, pH 4.4). The thickness, composition, and electrochemical behavior were characterized by x‐ray photoelectron spectroscopy, secondary ion mass spectrometry, ellipsometry, and electrochemical impedance spectroscopy. In borate buffer, oxide growth results in a two‐layer structure with an outer As2O3‐rich layer and ion transfer is mainly diffusion controlled. From the potential dependence of the film thickness a growth rate of 25 A/V was determined. Due to the formation of a Ga‐phosphate precursor layer in NH4H2PO4, films grow under field control which results in a time dependence of oxide thickness and composition. Under pseudosteady state conditions a growth rate of 28 A/V was obtained. Films formed in NH4H2PO4 have, except for the outer phosphate layer, a fairly uniform composition in depth with a significant enrichment of Ga2O3, and show a 40 times higher specific charge transfer resista...