The Design Of Multi Function Semiconductor Materials Tester

Conductive type,square resistance and resistivity semiconductor material is the most important characteristic parameter,through its judgments and measurement, can acquire different kinds of impurity concentration in the sample distribution. Therefore,in the semiconductor industry,we must quickly and accurately type conductive film on silicon wafers,the square resistance and resistivity of judgement, measurement,and grading.In this paper,analyzed the conductive type,square resistance and resistivity testing principle in detail,by comparing several test methods,using the three probes compensation method and double combination four-probe electrical measurement method.And compared with domestic manufacturers now commonly used deflection of the current indicator method and straight four-probe method,has high accuracy, measurement function without amendment,and have nothing to do with sample shape and spacing of probes,and be good at inhibiting probe vertical deviation from a straight line or mobile.This paper,by bleeding conductive type,sheet resistance and resistivity testing method with MCUμ'nSP^TM061A system to design a digital and intelligent conductive type,sheet resistance and resistivity tester,introduced the various component parts of the circuit and function in detail,as well as the corresponding software programming.Based on three probes Compensation method and double combination four-probe electrical measurement method,and used a 16-bit MCUμ'nSP^TM061 to control the high stability programmable constant current source circuit and low temperature coefficient,low noise amplifier circuit programmable, and the automatic conversion circuit range of a measurement circuit,which makes the device will automatically identify the sample resistivity,and in accordance with automatic switching resistivity size range,work independently,suppressed frequency interference and improved the measurement accuracy and intelligent level by using redundant channel method and average filtering method,.The practical result shows that:space probe have nothing to do with measurement,can automatically correct boundary effects and automatically select the range,greatly raising the device's data-processing capacity and accuracy,in addition operation is very convenient and efficient.Hence the device is of applicative valueand and can meet the needs of the production and teaching better.