Researching And Developing Of Intelligent Four-Probe Resistivity Meter's

Resistivity is a very important performance index in semiconductor material, because it will influence the performance of the device directly. We can get some important information such as the doping content from measuring it. At present, the direct current four probe testing method is widely used to measure resistivity in microelectronics. It is very strict to its testing precision and testing means. So, it is very meaning and valuable to develop and reform this method.In this paper I will primarily discuss the application of the resistivity of direct current four probes on the basis of analyzing several kinds of testing principle of four probes technology. I carry on organic combination of advanced digital technology and embedded technology, and have designed and developed a new intellectual digitization type of direct current four probes testers. The result of testing indicates that this instrument has totally reached the designing requirement, has already put into real work. On the other hand, this tester also has a characteristic of small volume, low cost, high dependability and low power dissipation.First of all I analyze and research the theoretical foundation of the probe tests, from Vanderbilt's principle. I establish the direct current four probes testing on the basic of compare among several testing methods through carefully deducing from several different arithmetic. Secondly, I use MSP430 as core of controlling and make all modules can cooperate work through programming. In addition I replace the wave circuit by embedded technology to reduce the systematic consumption. In this system, It can achieve permanent flow source circuit, data gather and deal with circuit and LCD display through adopting automatic control technology, In addition it can communicate with the PC. Finally, I design and produce the real circuit on the basis of carrying on emulation and obtaining anticipated result to every unit circuit, and provide test data and technical indicator of testing online.The innovation in this paper is that it can change range and deal with data automatically. It is not only can test the resistivity separately but also can communicate with PC through RS-232.In this way, it can improve the measuring precision through revising various kinds of errors by computer.