Design Of Silicon Constant Current Diode

With the popularization of electronic products in daily life, as well as the rapid development of semiconductor discrete devices industry, constant current source is facing the challenge of more accurate and more stable performance. Current Regulative Diode(CRD)is one of the most typical representative of the silicon constant current devices, with its very good constant current performance, low open voltage, high breakdown voltage and high stability advantages of electrical properties. Also, it is very cheap, flexible and simple to use in all kinds of constant current sources, voltage stabilizers and protection circuits.In this paper, a simple CRD was designed, which based on the structure of JFET. The process and method in the semiconductor manufacturing process are determined. By simulating the key parameters for CRD, one can further understand the effects of key parameters on the device electrical performance: the simulation results show that with the increase of channel concentration, device constant current value increases, open voltage also increases, the breakdown voltage of attenuation trend; with channel length increasing, which leads to the constant current value is smaller, open voltage and breakdown voltage basic remain unchanged; channel thickness growing mainly makes the open voltage of the device and constant current value increases and so on. We got the open voltage of 3.7V, the breakdown voltage of 114 V, constant current value of 40 mA, temperature coefficient of 0.20%/K, dynamic impedance of 69 k? of the CRD device. In this paper, the CRD device’s theoretical and simulation results are basically identical with results from factory flow, the measurement results indicate that using the process simulation software for semiconductor devices for experimental analysis is of great realistic significance.