Method for testing IDD at multiple voltages
AssigneeLSI Logic Corporation
InventorsErnest Allen, III, David Castaneda
Life of this patent
Estimating the term…
Abstract
According to one embodiment, a method of testing an integrated circuit is provided. The quiescent current measuring of an integrated circuit is measured at two voltages. The functional relationship between the current measurements is determined and compared against a predetermined functional relationship to determine whether a defect exists in the integrated circuit.
Claims20
A method for testing a semiconductor device, the method comprising:
- measuring for a first semiconductor device a first current at a first voltage and a second current at a second voltage;
- identifying a functional relationship between the first and second currents wherein the first and second voltages are set within a range of about 50 to 140% of a nominal supply voltage for the device;
- and
- comparing the functional relationship to a predetermined relationship to determine whether the device is defective, wherein the predetermined relationship is determined by at least one of evaluating the functional relationship for at least one other die on the same wafer or is determined from a plurality of dies fabricated previously.
A method for testing a semiconductor die, the method comprising:
- measuring for the semiconductor die at least two quiescent currents, the first current of the two quiescent currents measured when a first supply voltage is applied to a supply terminal of the die and the second current measured when a second supply voltage is applied to the supply terminal of the die wherein the first and second voltages are set within the range from 50 to 140% of a nominal supply voltage for the device;
- determining a measured ratio between the first and second currents;
- comparing the measured ratio with an expected ratio for quiescent currents;
- and
- determining if the die is defective when the measured ratio differs from the expected ratio by a predetermined threshold.
A method for testing a semiconductor device, the method comprising:
- measuring for a first semiconductor device a first current at a first voltage and a second current at a second voltage;
- identifying a functional relationship between the first and second currents wherein the functional relationship is a ratio of the first and second currents and the predetermined threshold is about 20% of the value determined for the ratio;
- and
- comparing the functional relationship to a predetermined relationship to determine whether the device is defective, wherein the predetermined relationship is determined by at least one of evaluating the functional relationship for at least one other die on the same wafer or is determined from a plurality of dies fabricated previously.
A method for testing a semiconductor device, the method comprising:
- measuring for a first semiconductor device a first current at a first voltage and a second current at a second voltage;
- identifying a fictional relationship between the first and second currents wherein the predetermined relationship comprises a running average of the functional relationship for the devices previously tested;
- and
- comparing the functional relationship to a predetermined relationship to determine whether the device is defective, wherein the predetermined relationship is determined by at least one of evaluating the functional relationship for at least one other die on the same wafer or is determined from a plurality of dies fabricated previously.
Dependencies are inferred from the claim text.