| 摘要 |
<p>An electrostatic discharge protection circuit formed as an integrated circuit chip, the chip comprising:
a first region of a first conductivity type;
a second region of a second conductivity type adjoining a first surface of the chip, the second region forming a first PN junction diode with the first region;
a third region of the second conductivity type separated from the second region and adjoining the first surface of the chip and enclosing a fourth region of the first conductivity type and a fifth region of the first conductivity type, the fourth and fifth regions adjoining the first surface, the fourth region forming a second PN junction diode with the third region and the fifth region forming a third PN junction diode with the third region;
a sixth region of the first conductivity type and a seventh region of the second conductivity type, the sixth and seventh regions being separated from the second and third regions and adjoining the first surface, the sixth region forming a fourth PN junction diode with the seventh region;
a first metal layer connecting the second and fourth regions;
a second metal layer connecting the fifth and seventh regions;
a third metal layer connecting the first and sixth regions; and
a fourth metal layer for carrying an input signal and connecting the first metal layer to a circuit to be protected by the electrostatic discharge protection circuit.</p> |
