Patent ID: 7783466

Claim:
A method comprising: measuring a characteristic of an integrated circuit (IC) chip at a plurality of temperatures; modeling to form a hardware model for the characteristic versus temperature based on the measuring; obtaining a known first target value of the characteristic for at least one temperature in the hardware model; determining a plurality of second target values for the characteristic for a corresponding plurality of temperatures in the hardware model, wherein in the case that the characteristic is threshold voltage, the determining includes calculating each second target value according to the following: Vt_target(T)=Vt_target(T 0 )+(Vt_hardware(T)−Vt_hardware T 0 )), where Vt_target (T) is the second target value for threshold voltage at a temperature T at which the second target value for the threshold voltage is to be determined and at which a value exists for the threshold voltage in the hardware model, Vt_target T 0 is the first target value at a temperature (T 0 ) at which the first target value for the threshold voltage is known and at which values for the threshold voltage exist in the hardware model, Vt_hardware(T) is a value for the threshold voltage at the temperature T in the hardware model and Vt_hardware (T 0 ) is a value for the threshold at the temperature T 0 in the hardware model, and wherein in the case that the characteristic further includes above-threshold current, the determining includes calculating each second target value of above-threshold current according to the following: J ⁡ ( T ) = J ⁡ ( T 0 ) ⁢ I ⁡ ( T ) I ⁡ ( T 0 ) ⁢ ( 1 + { g m I ⁢  T , V g ⁢ - g m I  T , ( V g - δ ⁢ ⁢ V t ) } ⁢ Δ ⁢ ⁢ V g ) T where J(T) is the second target value for the above-threshold current at a temperature T at which the second target value for the above-threshold current is to be determined and at which a value exists for the above-threshold current in the hardware model, J(T 0 ) is the first target value at a temperature (T 0 ) at which the first target value for the above-threshold current is known and at which values for the above-threshold current exist in the hardware model, I(T) is a value for the above-threshold current at the temperature T in the hardware model I(T 0 ) is a value for the above-threshold current at the temperature T 0 in the hardware model δV T is a difference between Vt_target(T) and Vt_hardware T, and ΔV g is a difference between Vt_target(T) and Vt_target(T 0 ), and g m is a derivative of above-threshold current (I) with respect to a gate bias ⅆ I d ⅆ V g , where Id is a drain current and Vg is a gate bias; and modeling to form a target model for the characteristic based on the first known target value and the plurality of second target values.