电化学C-V法对载流子浓度纵向分布的精确测量

Accurate Measurement of Vertical Distribution of Carriers Concentration by Electrochemical Capacitance-Voltage

电化学C-V法是当前测量化合物半导体载流子浓度纵向分布的非常重要的方法。用电化学C-V测试仪对外高内低、有较大浓度梯度的外延样品进行载流子浓度纵向分布测量时发现,内层低载流子浓度区域测试结果误差较大,主要是由测试系统引起的,由此提出了一种对结果的修正算法。通过对MBE制作专用样品测量证实,用该方法可得到数据准确可靠的测试结果。

Electrochemical capacitance-voltage （ECV） profiler is the most convenient method to characterize the vertical distribution of carriers concentration of compound semiconductor. It was found that the carrier concentration error in inner layer was great when the sample was measured by ECV, whose carrier concentration in the outer layer was bigger than that in inner layer with large concentration grad. It was observed that the error mainly caused by the testing system, on the basis of which a modified algorithm was presented. The validity of this modified algorithm was confirmed by the tested results of special samples grown by MBE, measurement results can be achieved reliably.