电阻率对电容法测Si片厚度的影响

Influence of Resistivity on Wafer Thickness Test by Capacitance Method

在对电容法测量Si片厚度的原理分析基础上,根据电阻率与介质介电常数ε的对应关系,分析了用电容法测试Si片厚度时,电阻率及电阻率均匀性对测试结果的影响,并采用千分尺(有接触测试)、ADE6034及Wafer Check 7000(电容法测试)分别对不同电阻率及电阻率均匀性的样品进行测试比对。实验结果证明,电容法可以测量高电阻率Si片的厚度等几何参数,但不能测量电阻率均匀率较差的Si片。同时,校正电容法测量设备时,以校正样片电阻率与被测Si片电阻率范围接近为原则。

Through capacitance method based on its principle analysis,according to the corresponding relation between the resistivity and the electric medium constant ε,the influence on the result of wafer thickness test by their resistivity and uniformity is analyzed.The test results between samples with different resistivities and uniformities are compared,using micrometer（the ＂touch test＂ method） and ADE6304 or Wafer Check 7000（the capacitance method） respectively.The test result proves that the geometric parameter of the wafers with high resistivity can be measured by capacitance method,but the wafers with less resistivity uniformity can＇t be measured.Furthermore,the proximity principle of the range of the sample resistivity and the wafer resistivity to be measured must be fellowed for correcting the capacitance test set.