Application Of Automatic Controlling And Image Recognition Technology In A Fout-Point Probe Instrument

Four-point probe technology is a special method to measure the resistivity of semiconductor. It was put forward several decades ago. This method includes abundant theories and it has been utilized widely in the technology of semiconductor production. Nowadays, the technology of IC production develops very fast. The demand of the semiconductor microareas'performance is higher and higher. The four-point probe technology is also faced with more severe challenge simultaneously. In view of this situation, we developed a distinctive four-point probe measuring instrument. This instrument utilized automatic controlling technology by PC and microcontroller to fulfill the whole measuring course. Furmore, it used image recognition technology to achieve the precise localization of the probes. In this paper, I elaborated my own work in this project, then our instrument was introduced wholly.Firstly, in the part of introduction, the background of four-point probe technology, the general conditions of our measuring instrument and the main contents of my paper were summarized. After that, the theory of four-point probe measurement was briefly explained. This part includes the principles of each method using four-point probe and other correlated theories. The most important item here is the improved Rymaszewski method used by square four-point probe. Then the technological contents of our instrument was introduced in details. These contents was written with concise words and a lot of photos. This part includes the circuit around the microcontroller, the designing of the software in PC, and the image recognition technology for probes location. In the part describing the circuit around the microcontroller, mainly, the principles of the constant current source citcuit was introduced. This circuit is a critical composite section of the lower circuit, and it is an achievement gained by us through lots of practical experiments and debugging. At last, I generalized the method for using our instrument, the items to be noticed necessarily, the course of data procession and the main features of our product.