三维集成叠层键合结构的电容电压表征技术

发布时间：2018-06-22 21:07

本文选题：三维集成 + 电容-电压曲线　；参考：《南京邮电大学》2017年硕士论文

【摘要】：三维集成是当前集成电路技术发展方向之一,而叠层键合结构是三维集成技术的基本结构,研究其检测和表征技术具有重要科学意义和实用价值。为此,本文在深入研究叠层键合结构电容-电压特性的基础上,提出了一种非破坏性参数提取方法,并通过数值模拟和实验进行了验证。其主要工作包括:第一,建立了MIS结构精确的低频和高频电容-电压模型。在理想结构基本模型基础上,对衬底表面势、反型条件和弱反型区表达式进行了校准,使其解析结果相对数值结果的精确度提高到了99%以上,并在此基础上研究了界面态对MIS结构电容-电压特性的影响。第二,建立了理想叠层键合结构的低频和高频电容-电压模型。基于MIS结构精确电容-电压模型,推导了不同掺杂类型的理想叠层键合结构的低频和高频电容-电压关系表达式,并利用二维半导体器件仿真软件MEDICI进行了数值模拟验证。结果表明解析结果和数值结果吻合良好。进而为了探讨该结构电容-电压特性的物理本质,深入研究了空间电荷层、半导体表面势以及金属层电势随外加电压的变化关系,以及半导体掺杂浓度、绝缘层厚度等结构参数对其电容-电压特性的影响。第三,建立了实际叠层键合结构的低频和高频电容-电压模型。通过考虑金属与半导体功函数差、绝缘层固定电荷、界面态等因素,对叠层键合结构的低频和高频电容-电压关系表达式进行了修正。结果表明实际叠层键合结构的电容-电压模型呈现出高度的复杂性,不同的半导体表面势状态可导致四种不同形态的电容-电压曲线,本文对其机理进行了分析,并利用二维数值模拟进行了验证。第四,提出了一种利用电容-电压法无损提取叠层键合结构参数的方法。基于上述模型我们利用低频和高频的饱和值分别提取绝缘层厚度和半导体掺杂浓度,利用低频曲线的零点和特征点提取绝缘层固定电荷,利用参数识别的方法提取界面态密度。数值模拟表明所得到的提取值与理论值的相对误差基本都在6%以下,证明了提取方法简单且准确。第五,研制了MIS结构和叠层键合结构,并进行了参数提取。利用氧化、淀积等手段,制备了以铜为金属层的MIS结构,进而利用铜铜键合技术,将两片MIS结构背靠背键合,从而得到叠层键合结构。而后对两种结构的样品进行了SEM测试和高频电压-电容特性测试,并利用前述提取方法,成功地提取了样品的相关物理参数,证实了模型和理论的正确性和实用性。本文的工作为评估三维集成叠层键合结构的可靠性提供了一种非破坏性的表征方法,简单方便、成本低廉、且精度高,具有重要的工程价值和实际意义。
[Abstract]:3D integration is one of the development directions of IC technology, and laminated bonding structure is the basic structure of 3D integration technology. It is of great scientific significance and practical value to study the detection and characterization technology. Therefore, based on the in-depth study of capacitance-voltage characteristics of laminated bonding structures, a non-destructive parameter extraction method is proposed, which is verified by numerical simulation and experiments. The main works are as follows: first, the accurate models of low frequency and high frequency capacitances-voltage of MIS structure are established. Based on the basic model of ideal structure, the surface potential, inversion condition and weak inversion region expressions of substrate are calibrated, and the accuracy of analytical results relative to numerical results is improved to more than 99%. On this basis, the influence of interface state on the capacitance-voltage characteristics of MIS structure is studied. Secondly, the low frequency and high frequency capacitance-voltage models of ideal laminated bonding structures are established. Based on the exact capacitance-voltage model of MIS structure, the expressions of low-frequency and high-frequency capacitance-voltage relationships of ideal laminated bonding structures with different doping types are derived, and the simulation results are verified by the two-dimensional semiconductor device simulation software MEDICI. The results show that the analytical results are in good agreement with the numerical results. In order to study the physical nature of the capacitance-voltage characteristics of the structure, the relationship between the space charge layer, the surface potential of the semiconductor and the potential of the metal layer with the applied voltage, as well as the doping concentration of the semiconductor, are studied. The influence of insulation thickness and other structural parameters on the capacitance-voltage characteristics. Thirdly, the low-frequency and high-frequency capacitance-voltage models of practical laminated bonding structures are established. By taking into account the difference of work function between metal and semiconductor, the fixed charge of insulating layer and the interface state, the expressions of low-frequency and high-frequency capacitance-voltage relationships of laminated bonding structures are modified. The results show that the capacitance-voltage model of the actual laminated structure presents a high degree of complexity. Different surface potential states of semiconductors can lead to four different types of capacitance-voltage curves. The mechanism is analyzed in this paper. It is verified by two-dimensional numerical simulation. Fourthly, a method of nondestructive extraction of laminated structure parameters by capacitance-voltage method is proposed. Based on the above model, the thickness of insulation layer and the concentration of semiconductor doping are extracted from the saturation values of low frequency and high frequency, respectively. The zero and characteristic points of low frequency curve are used to extract the fixed charge of insulation layer, and the density of interfacial states is extracted by parameter identification. Numerical simulation shows that the relative error between the extracted value and the theoretical value is less than 6%, which proves that the extraction method is simple and accurate. Fifthly, MIS structure and laminated bonding structure are developed, and parameters are extracted. By means of oxidation and deposition, the MIS structure with copper as metal layer was prepared, and then two pieces of MIS structure were bonded back to back by copper bonding technology, and the laminated bonding structure was obtained. Then the samples with two structures were tested by SEM and the characteristics of high-frequency voltage-capacitance. The physical parameters of the samples were extracted successfully by using the above extraction method. The correctness and practicability of the model and theory were verified. The work in this paper provides a nondestructive representation method for evaluating the reliability of 3D integrated laminated bonding structures. It is simple, convenient, low cost and high precision. It has important engineering value and practical significance.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN407

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