Behavior of Electrodeposited Cd and Pb Schottky Junctions on CH3-Terminated n-Si(111) Surfaces
Behavior of Electrodeposited Cd and Pb Schottky Junctions on CH3-Terminated n-Si(111) Surfaces
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CH3 封端的 n-Si(111) 表面上电沉积 Cd 和 Pb 肖特基结的行为
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
N. Lewis
中科院分区：
文献类型：
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作者：
S. Maldonado;N. Lewis
本文报道了在H和CH_3封端的n型Si（111）表面电沉积Cd或Pb，制备了n-Si/Cd和n-Si/Pb肖特基结。对于非简并（n-）和简并（n+-）掺杂的H-Si（111）电极，Cd和Pb容易电镀和氧化剥离，与Si/溶液和Si/金属结处的小势垒高度（Phib）一致。Cd或Pb在简并掺杂的CH_3封端的n ~+-Si（111）电极上的电沉积与Cd或Pd在H封端的n ~+-Si（111）电极上的电沉积在相同的电位下发生。然而，在非简并掺杂的CH 3封端的n-Si（111）表面上的电沉积显著地向更负的外加电位偏移（分别为-130 mV和-347 mV），并且电沉积金属的阳极剥离严重衰减，这表明在非简并掺杂的n型CH 3-Si（111）表面上的接触具有大的Phib值。无论是镉或铅，干的，电沉积肖特基结上的电流-电压测量表明，更大的值Phib得到CH 3终止的n-Si（111）表面比H终止的n-Si（111）表面。计时电流数据表明，CH 3-Si（111）表面具有一个数量级的低密度的金属电沉积的成核位点比H-Si（111）表面，证明了高程度的结构钝化提供的CH 3-Si表面改性。
n-Si/Cd and n-Si/Pb Schottky junctions have been prepared by electrodeposition of Cd or Pb from acidic aqueous solutions onto H-terminated and CH3-terminated n-type Si(111) surfaces. For both nondegenerately (n-) and degenerately (n+-) doped H–Si(111) electrodes, Cd and Pb were readily electroplated and oxidatively stripped, consistent with a small barrier height (Phib) at the Si/solution and the Si/metal junctions. Electrodeposition of Cd or Pb onto degenerately doped CH3-terminated n+-Si(111) electrodes occurred at the same potentials as Cd or Pd electrodeposition onto H-terminated n+-Si(111). However, electrodeposition on nondegenerately doped CH3-terminated n-Si(111) surfaces was significantly shifted to more negative applied potentials (by −130 and −347 mV, respectively), and the anodic stripping of the electrodeposited metals was severely attenuated, indicating large values of Phib for contacts on nondegenerately doped n-type CH3–Si(111) surfaces. With either Cd or Pb, current–voltage measurements on the dry, electrodeposited Schottky junctions indicated that much larger values of Phib were obtained on CH3-terminated n-Si(111) surfaces than on H-terminated n-Si(111) surfaces. Chronoamperometric data indicated that CH3–Si(111) surfaces possessed an order-of-magnitude lower density of nucleation sites for metal electrodeposition than did H–Si(111) surfaces, attesting to the high degree of structural passivation afforded by the CH3–Si surface modification.