Electrical characteristics of Mo/4H-SiC Schottky diodes having ion-implanted guard rings: temperature and implant-dose dependence
Electrical characteristics of Mo/4H-SiC Schottky diodes having ion-implanted guard rings: temperature and implant-dose dependence
复制标题
DOI：
10.1088/0268-1242/26/8/085003
复制
发表时间：
2011-08
影响因子：
1.9
通讯作者：
A. Latreche;Z. Ouennoughi;A. Sellai;R. Weiss;H. Ryssel
中科院分区：
文献类型：
--
作者：
A. Latreche;Z. Ouennoughi;A. Sellai;R. Weiss;H. Ryssel
基于标准的电子发射模型和势垒高度为高斯分布的假设，分析了4 H-SiC上钼（Mo）肖特基二极管离子注入保护环的电学特性。对于边缘端接，使用由碳和铝离子注入区制造的高电阻率保护环。利用电流-电压-温度（I-V-T）和电容-电压（C-V）测量方法，对不同栅金属化结构的碳化硅（4 H-SiC）肖特基二极管上钼的势垒高度进行了提取。肖特基势垒高度（SBH）的特征被认为是在有关的碳或铝注入保护环的特定剂量。在303-473 K温度范围内，肖特基接触的理想因子在1.02 - 1.24之间，表现出良好的肖特基特性.测得的SBH在0.92和1.17 eV之间，在相同的温度范围内从I-V-T特性。势垒高度的变化，这是显着的温度和辐射剂量依赖性，很好地拟合到一个单一的高斯分布函数。实验结果表明，当碳注入剂量为1.75 × 1014 cm-2时，器件的平均势垒高度为1.22 eV，零偏标准偏差σ0 = 0.067 V。此外，根据高斯分布模型修改的Richardson图得到的平均势垒高度（）和Richardson常数（A*）分别为1.22 eV和148 A cm−2 K−2。从该图中获得的A* 值与n型4 H-SiC的理论值146 A cm−2 K−2非常接近。因此，可以得出结论，Mo/4 H-SiC接触的正向（I-V）特性的温度依赖性可以成功地解释的基础上的高斯分布的障碍的电子发射导电机制。
The electrical characteristics of ion-implanted guard rings for molybdenum (Mo) Schottky diodes on 4H-SiC are analyzed on the basis of the standard thermionic emission model and the assumption of a Gaussian distribution of the barrier height. For edge termination, high-resistivity guard rings manufactured by carbon and aluminum ion-implanted areas were used. Extractions of barrier heights of molybdenum on silicon carbide (4H-SiC) Schottky diodes have been performed on structures with various gate metallization, using both current–voltage–temperature (I–V–T) and capacitance–voltage (C–V) measurements. Characteristic features of the Schottky barrier height (SBH) are considered in relation to the specific dose of the carbon- or aluminum-implanted guard ring. Contacts showed excellent Schottky behavior ideality factors between 1.02 and 1.24 in the range of 303–473 K. The measured SBHs were between 0.92 and 1.17 eV in the same temperature range from I–V–T characteristics. The variations in the barrier height, which is significantly temperature- and implantation-dose-dependent, are well fitted to a single Gaussian distribution function. Experimental results agree reasonably well by using this approach, particularly for carbon implantation dose of 1.75 × 1014 cm−2, and a mean barrier height () of 1.22 eV and zero bias standard deviation σ0 = 0.067 V have been obtained. Furthermore, the modified Richardson plot according to the Gaussian distribution model resulted in a mean barrier height () and a Richardson constant (A*) of 1.22 eV and 148 A cm−2 K−2, respectively. The A* value obtained from this plot is in very close agreement with the theoretical value of 146 A cm−2 K−2 for n-type 4H-SiC. Therefore, it has been concluded that the temperature dependence of the forward (I–V) characteristics of the Mo/4H-SiC contacts can be successfully explained on the basis of a thermionic emission conduction mechanism with Guassianly distributed barriers.