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US 6,586,317 B1Granted
Method of forming a zener diode in a npn and pnp bipolar process flow that requires no additional steps to set the breakdown voltage
AssigneeNational Semiconductor Corporation
InventorsVladislav Vashchenko, Andy Strachan, Peter Hopper
Life of this patent
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Abstract
A zener diode is formed in a bipolar or BiCMOS fabrication process by modifying the existing masks that are used in the bipolar or BiCMOS fabrication process, thereby eliminating the need for a separate doping step. In addition, the reverse breakdown voltage of the zener diode is set to a desired value within a range of values by modifying the area of a new opening in one of existing masks.
Claims21
A method of forming a device on a semiconductor material, the method comprising the steps of:
- forming a first zener region of a first conductivity type, the first zener region contacting the semiconductor material;
- forming a second zener region of a second conductivity type, the second zener region contacting the first zener region;
- and
- forming a layer of epitaxial material on the semiconductor material, the layer of epitaxial material having a top surface and a bottom surface, a first region that extends from the top surface to the first zener region, and a second region that extends from the top surface to the second zener region, the first region having the first conductivity type and the second region having the second conductivity type.
1 more element
Dependencies are inferred from the claim text.