| 摘要 |
A semiconductor body has a first region of one conductivity type coupled to a first electrode. A second region of the opposite conductivity type is coupled to a second electrode and is provided within the first region to form a first pn junction with the first region. At least one further region of the opposite conductivity type is formed within the first region and spaced from the second region so as to form a further pn junction with the first region with each of the first and further pn junctions making a contribution to the capacitance of the diode. This capacitance varies during operation of the diode with a reverse-biasing voltage applied between the first and second electrodes. A coupling region of the opposite conductivity type and more lowly doped than the second and further regions provides a resistive path for free charge carriers of the opposite conductivity type between the second and further region and is sufficiently lowly doped that when a reverse-biasing voltage applied between the first and second electrodes reaches a predetermined value, at least part of the coupling region becomes depleted of free charge carriers to interrupt the resistive path and thereby resistively decouple the second and further region so that the capacitive contributions of the first and further pn junctions are no longer coupled in parallel with one another by the resistive path and the overall capacitance of the diode is reduced.
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