无测试图形薄层电阻测试仪及探针定位

Research on Instrument for Testing Sheet Resistance Without Testing Pattern and the Orientation of Probes

研制出检测 U L SI芯片的薄层电阻测试仪 ,可用于测试无图形样片电阻率的均匀性 ,用斜置的方形四探针法 ,经显微镜、摄像头及通信口接入计算机 ,从计算机显示器观察 ,用程序及伺服电机控制平台和探针移动 ,使探针处于规定的位置 ,实现自动调整、测试 ;对测试系统中的探针游移造成的定位误差进行分析 ,推导出探针游移产生误差的计算公式 ,绘制了理论及实测误差分布图 ;测出无图形 10 0 m m样品电阻率 ,并绘制成等值线 Mapping图 .

A new type of instrument for testing sheet resistance of ULSI wafers by an inclined four-point square probe is introduced.It can be used in the measurement of resistivity uniformity for a wafer specimen without testing pattern.The probes are observed on the display of a computer by a microscope and a head of pickup camera.The testing location of the probes and specimen table is regulated by the way of program control and servo engines.The affection upon measuring results arising from the wander of probes is also discussed and the calculating equation is deduced.The distributing graphs arising from the wander of probes are drawn in theory calculating and in practical testing.A wafer specimen of four inches is measured with the equipment and an equal-value line Mapping graph is drawn.