Large magnetoresistance in Si:B-SiO2-Al structures
Large magnetoresistance in Si:B-SiO2-Al structures
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DOI：
10.1063/1.2832614
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发表时间：
2008-02
影响因子：
3.2
通讯作者：
J. J. Schoonus-J.;J. Kohlhepp;Hjm Henk Swagten;B. Koopmans
中科院分区：
文献类型：
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作者：
J. J. Schoonus-J.;J. Kohlhepp;Hjm Henk Swagten;B. Koopmans
在掺硼的Si-SiO_2-Al结构中观察到了随磁场变化的8个数量级的电阻。为了确定控制这一现象的基本机制，作为界面能垒的氧化层的厚度已经通过改变暴露在氧等离子体中的时间来改变。其次，通过原位X射线光电子能谱测量对化学成分进行了监测。从电流-电压测量中，我们观察到在低温下，超薄的SiO_2层提供了触发碰撞电离的自催化过程的动能。磁场抑制了碰撞电离到较高电场的开始，导致了较大的磁阻。在掺硼的Si-SiO_2-Al结构中，观察到与磁场有关的八个数量级的电阻变化。为了确定控制这一现象的基本机制，作为界面能垒的氧化层的厚度已经通过改变暴露在氧等离子体中的时间来改变。其次，通过原位X射线光电子能谱测量对化学成分进行了监测。从电流-电压测量中，我们观察到在低温下，超薄的SiO_2层提供了触发碰撞电离的自催化过程的动能。磁场抑制了碰撞电离到更高电场的开始，导致了大的磁电阻。
A magnetic-field-dependent resistance change of eight orders of magnitude is observed in boron-doped Si-SiO2-Al structures. In order to identify the elementary mechanisms governing this phenomenon, the thickness of the oxidic layer, which is used as an interface energy barrier, has been varied by changing the exposure time to an oxygen plasma. Next, the chemical composition has been monitored by in situ x-ray photoelectron spectroscopy measurements. From current-voltage measurements, we observe that at low temperatures, an ultrathin SiO2 layer provides the kinetic energy to trigger an autocatalytic process of impact ionization. A magnetic field suppresses the onset of impact ionization to higher electric fields, resulting in a large magnetoresistance.A magnetic-field-dependent resistance change of eight orders of magnitude is observed in boron-doped Si-SiO2-Al structures. In order to identify the elementary mechanisms governing this phenomenon, the thickness of the oxidic layer, which is used as an interface energy barrier, has been varied by changing the exposure time to an oxygen plasma. Next, the chemical composition has been monitored by in situ x-ray photoelectron spectroscopy measurements. From current-voltage measurements, we observe that at low temperatures, an ultrathin SiO2 layer provides the kinetic energy to trigger an autocatalytic process of impact ionization. A magnetic field suppresses the onset of impact ionization to higher electric fields, resulting in a large magnetoresistance.