Development Of Measurement System For Charge Carrier Mobility Based On Virtual Instrument

Carrier mobility is one of the most important characteristic parameters of semiconductors from which the electron transport property of materials can be obtained. Therefore, the measures of the carrier mobility are very important for the research and production of the semiconductor materials.With the development of science and technology, a new kind of instrument called virtual instruments appears. A virtual instrument is a system with interactive graphic interfaces based on computers. It consists of a computer, application softwares, and instrument hardwares. Its development, reflected by one of the famous products, LabVIEW, will be introduced briefly.In this paper, several traditional testing methods and instruments for the carrier mobility are introduced and discussed. To solve the problems such as low accuracy, rigorous requirements and high cost coming from the traditional instruments, a measure system is developed for the carrier mobility according to the method of carrier extraction by linearly increasing voltage (CELIV), regarding LabVIEW8.60 as a design platform. The circuits of various components are introduced. The design method and realization of measure system are discussed in detail, which include the linearly increasing voltage control, the data acquisition, the data storage, the data redisplay, and so on.Finally, the system debugging and testing for the measure system, as well as the analysis of the testing results, have been carried on. It performs well in data acquisition, data storage, data redisplay and so on. Furthermore, the software has outstanding abilities in parameter setting and secondary development, which shows wide potential applications.