Investigation of the electrical and thermal characteristics of CMOS zener diodes.
24 September 1986
Diodes have existed for approximately 80 years. In the past, diodes consisted of vacuum tubes. Today through Very Large Scale Integration technology, a diode can be made so small that it can be placed inside a human hair. A specific type of diode, called a zener diode, is the subject of this project. A zener diode can be used as a voltage clamp in a protection circuit or as a reference voltage device. Recent designs often include certain undesirable characteristics, such as a soft knee effect, unevenly doped junction, hot spots, and large parasitic capacitance. This paper deals with the improvement of the electrical and thermal properties of a zener diode. Diodes of several geometries were investigated and tested to evaluate the electrical and thermal performance of the pn junction. The test results indicate that the zener diode properties deteriorate when the geometry includes corners. A circular geometry is the solution.