片式钽电容器肖特基发射电流的机理分析  

Mechanism of Schottky emission current in chip tantalum capacitors

作　　者：邓俊涛 钟山 代东升 胡丹单 余伟 潘齐凤 DENG Juntao;ZHONG Shan;DAI Dongsheng;HU Dandan;YU Wei;PAN Qifeng(China Zhenhua Group Xinyun Electronics Components Corporation,Guiyang 550018,China)

机构地区：[1]中国振华(集团)新云电子元器件有限责任公司,贵州贵阳550018

出　　处：《电子元件与材料》2024年第12期1449-1455,共7页Electronic Components And Materials

摘　　要：基于肖特基发射电流传导机制,研究一种测试方法,能够推导计算片式钽电容器的肖特基势垒,并分析肖特基发射电流的形成原因,进而评估击穿时间,通过半定量分析阴极制备杂质残留,提出了片式钽电容器的一种混合结构模型。结果表明,MnO_(2)阴极掺杂样品组的肖特基势垒低,击穿时间短;非掺杂组的肖特基势垒高,击穿时间长。说明阴极材料中的金属杂质是导致片式钽电容器高温漏电流增大乃至击穿的主要原因。在对片式钽电容器进行加速寿命试验时,可以利用此方法和模型评估样品的可靠性和工艺缺陷,为失效机理分析、工艺优化和后续加固设计提供理论指导。Based on the conduction mechanism of Schottky emission current,a test method was established to measure the Schottky barrier of Ta-Ta_(2)O_(5)-MnO_(2) chip tantalum capacitors,which can evaluate the time-to-failure of the capacitors and semi-quantitative analyze the residue impurity in the cathode.The I-V and I-T curves of the capacitors were characterized,and the Schottky emission barrier was calculated.The mechanism of Schottky emission current was analyzed.And a mixed structure model was proposed with MIS(Metal-Insulator-Semiconductor)and MIM(Metal-Insulator-Metal)structure for the tantalum capacitors.The results show that the barrier height of the doped MnO_(2) cathode sample is low with short breakdown time,and vice versa for the undoped samples.It is shown that the metal impurity in the cathode is the main reason to deteriorate the leakage current at high temperature,which causes the breakdown of capacitors.This method and model can be used to evaluate the sample reliability and process defects,which provide theoretical guidance for failure analysis,process optimization and subsequent reinforcement design.

关 键 词：肖特基 界面势垒 电流传导 击穿 

分 类 号：TM535.1[电气工程—电器]