| 摘要 |
An improved zener diode formed in a semiconductor wafer having a primary surface, the zener diode having a PN junction buried beneath the surface. The diode includes a pair of spaced contacts on the surface, the first located on one region and the second located on another laterally spaced region of the surface, to establish a current path through the diode. A replica device is formed on the same wafer generally replicating the physical dimensions of the zener diode. The replica device has a pair of spaced surface contacts located on spaced regions of the surface with a replica current path between them having substantially the same resistance as the on-resistance of the current path of the diode, the replica current path replicating the current path except that it has no PN junction. The zener and the replica device are coupled together in a manner so that the voltage across the replica device will be subtracted from the voltage across the diode to generate a difference voltage which will be substantially independent of changes in series resistance of the current path of the zener diode due to variations in wafer manufacturing process or in ambient temperature when the diode is being used.
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