On-chip variance detection for integrated circuit devices
AssigneeTexas Instruments Incorporated
InventorsKevin M. Ovens, Alan S. Bass, Jay A. Maxey
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Abstract
A process variance detection technique for detecting fabrication processing variances in integrated circuit components, such as resistors or MOSFETs, is based on the decreased sensitivity to processing variations exhibited by components that are up-sized relative to similar components with nominal dimensions. Detection circuitry includes detection components with both nominal and up-sized dimensions, and variance detection involves detecting the differences in operational response of the nominal and up-sized detection components. For bipolar logic, resistors are fabricated with up-sized widths, while for MOS logic, MOSFETs are fabricated with up-sized gate lengths.
Claims14
An on-chip variance detection method for detecting variances in integrated circuit (IC) components, such as result from fabrication process variations, comprising the steps:
- fabricating at least one nominal MOSFET and at least one up-sized MOSFET;
- said up-sized MOSFET being fabricated with a gate length that is sufficiently greater than a gate length of said nominal MOSFET such that said up-sized MOSFET is significantly less affected by fabrication process variations than said nominal MOSFET;
- measuring an operational response of said nominal MOSFET relative to an operational response of said up-sized MOSFET, and converting that measurement into a variance indication signal representative of fabrication process variations.
An on-chip variance detection method for detecting variances in selected integrated circuit (IC) components, such as result from fabrication process variations, comprising the steps:
- fabricating at least one nominal detection component and at least one up-sized detection component;
- said up-sized detection component being fabricated with at least one dimension that is sufficiently greater than a corresponding dimension of said nominal detection component that said up-sized detection component is significantly less affected by IC component variances than said nominal detection component;
- measuring an operational response of said up-sized detection component relative to an operational response of said nominal detection component, and converting that measurement into a variance indication signal representative of fabrication process variations;
- and
- in response to the variance indication signal, compensating for fabrication process variations.
An on-chip variance detection circuit for detecting variances in integrated circuit (IC) components, such as result from fabrication process variations, comprising:
- at least one nominal MOSFET and at least one up-sized MOSFET;
- said up-sized MOSFET having a gate length that is sufficiently greater than a gate length of said nominal MOSFET such that said up-sized MOSFET is significantly less affected by fabrication process variations than said nominal MOSFET;
- detection circuit for detecting on operational response of said up-sized MOSFET relative to said nominal MOSFET, and generating a variance indication signal representative of fabrication process variations.
A circuit for detecting variations in MOSFET components comprising;
- a nominal detection MOSFET with a nominal gate length;
- an up-sized detection MOSFET with an up-sized gate length that is sufficiently greater than the nominal gate length such that said up-sized MOSFET is significantly less affected by fabrication process variations than said nominal MOSFET;
- a first current source coupled to the nominal detection MOSFET;
- a second current source coupled to the up-sized detection MOSFET;
- and
- a differential transistor pair coupled to the nominal detection MOSFET and the up-sized detection MOSFET for comparing the voltage across the nominal detection MOSFET with the voltage across the up-sized detection MOSFET.
Dependencies are inferred from the claim text.