四探针电阻率微区测量改进的Rymaszewski法厚度修正

Thickness Correction for the Measurement of the Resistivity for Micro-Areas by Using the Improved Rymaszewski Method with the Square Four-Point Probe

为了解决四探针技术在微区测量中不能测试较厚样品的问题,提出了一种厚度修正方法.该方法基于镜像源理论,以样品的上下边界为镜面,反复镜像电流源得到无限系列镜像源.将这些镜像源所产生的电位对测试点的影响进行叠加,推导出利用改进的Rymaszewski方形四探针法进行电阻率测量时的厚度修正公式,又利用规范化拟合法得到了多项式.修正后的结果反映了样品的真实电阻率,实验结果验证了该修正公式的正确性,从而完善了改进的Rymaszewski方形四探针的微区测量方法,使该方法能够应用到实际的测量中,提高了其实用性.

In order to solve the problem that the square four-point probe technique cannot be used in the measurement of the resistivity for micro-areas, a thickness correction method, based on the theory of mirror image of the electric current sources, was presented. Taking the top and bottom boundaries of specimens as mirrors, an infinite series of mirror image sources was obtained after repeatedly imaging the current sources. The influences of the voltages, arisen from these mirror image sources, on the test points were summarized, then a thickness correction formula was derived for measurement of the resistivity by using the improved Rymaszewski method with a square four-point probe.In addition, the thickness correction formula was also expressed as a polynomial by using a normalized matching. The corrected results reflect the sample＇ s real resistivity and the experimental results confirm the obtained thickness correction formula. This theory consummated the improved Rymaszewski method for square four-point probe measurement, ensured four-point probe measurement technique to be used in practical measurement ,and improved its feasibility.