Polysilicon resistors with high sheet resistance
AssigneeTexas Instruments Incorporated
InventorsYanbiao Pan, Pushpa Mahalingam
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Abstract
An integrated circuit includes a dielectric isolation structure formed at a surface of a semiconductor substrate and a polysilicon resistor body formed on the dielectric isolation structure. The polysilicon resistor body includes an N-type dopant having an N-type dopant concentration, nitrogen having a nitrogen concentration, and carbon having a carbon concentration. The sheet resistance of the resistor body is greater than 5 kΩ/square.
Claims20
A method of fabricating an integrated circuit, the method comprising:
- forming a polysilicon resistor body over a semiconductor substrate;
- and
- implanting an N-type dopant, nitrogen and carbon into the polysilicon resistor body, wherein:
- the N-type dopant is implanted into the polysilicon resistor body with no tilt;
- the nitrogen is implanted into the polysilicon resistor body with no tilt;
- and
- the carbon is implanted into the polysilicon resistor body using a tilt axis having a tilt angle of about nine degrees and a rotation of a long axis of the polysilicon resistor body about four degrees with respect to the tilt axis.
A method of fabricating an integrated circuit, the method comprising:
- forming a polysilicon resistor body over a semiconductor substrate;
- implanting phosphorus with a dose of about 6.5E14 cm−2 at an energy of about 30 keV with no tilt;
- implanting nitrogen with a dose of about 1.0E15 cm−2 at an energy of about 20 keV with no tilt;
- and
- implanted carbon at a dose of about 2.0E15 cm−2 and an energy of about 7 keV using a tilt angle of about nine degrees and a rotation of a long axis of the polysilicon resistor body about four degrees with respect to the tilt axis.
A method of fabricating an integrated circuit, the method comprising:
- forming a dielectric layer over a semiconductor substrate;
- forming a polysilicon resistor body over the dielectric layer;
- implanting an N-type dopant into the polysilicon resistor body with no tilt;
- implanting nitrogen into the polysilicon resistor body with no tilt;
- and
- implanting carbon into the polysilicon resistor body using a tilt axis having a tilt angle of about nine degrees and a rotation of a long axis of the polysilicon resistor body about four degrees with respect to the tilt axis.
Dependencies are inferred from the claim text.