Integrated transistor and protection diode and fabrication method
AssigneeTexas Instruments Incorporated
InventorsHaian Lin, Frank Baiocchi
Life of this patent
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Abstract
Disclosed examples provide integrated circuits including a source down transistor with a gate, a body region, an n-type source region, an n-type drain region, a p-type body contact region below the n-type source region which extends to a first depth, along with a protection diode which includes an n-type cathode region, and a p-type anode region below the n-type cathode region, where the breakdown voltage of the protection diode is defined by adjusting the relative doping concentrations and/or the vertical locations of the p-type anode region with respect to the n-type cathode region.
Claims14
An integrated circuit (IC), comprising:
- a p-type semiconductor substrate, including a first substrate region, and a second substrate region spaced from the first substrate region;
- a transistor in the first substrate region, including:
- a gate disposed over a gate dielectric layer over a top surface of the semiconductor substrate in the first substrate region, and laterally extending between first and second ends,
- a p-type body region under a first portion of the gate dielectric layer in the first substrate region,
- an n-type source region disposed in a portion of the body region under a second portion of the gate dielectric layer below the first end of the gate in the first substrate region,
- a source contact trench etched through a portion of the n-type source region to expose the p-type body region,
- a p-type contact region electrically connecting to the exposed p-type body region at a bottom of the source contact trench,
- a conductive source contact structure electrically connecting the n-type source region and the p-type contact region,
- an n-type drain region disposed below the top surface of the semiconductor substrate in the first substrate region, the n-type drain region including a first portion under a third portion of the gate dielectric layer adjacent to the p-type body region, and a second portion laterally spaced from the second end of the gate, and
- an n-type drain contact region disposed in the n-type drain region in the first substrate region laterally spaced from the second end of the gate;
- and
- a protection diode in the second substrate region, including:
- an n-type cathode region disposed in the second substrate region below the top surface of the semiconductor substrate, and
- an n-type cathode contact region disposed in the n-type cathode region,
- a p-type anode region with a doping concentration determined by a desired diode breakdown voltage, the p-type anode region disposed in the second substrate region below the n-type cathode region.
Dependencies are inferred from the claim text.