Low-voltage IC test for defect screening

A method for testing integrated circuits comprising:

• receiving a first voltage signal of a value less than a threshold transistor turn on voltage of a circuit's transistors, at one or more signal inputs of a voltage network provided in an integrated circuit;
• measuring a first current leakage at signal connectors of said voltage network on said voltage network;
• applying a defect accelerating stress to said voltage network;
• receiving a second voltage signal of a value less than a threshold transistor turn on voltage of a circuit's transistors, at one or more signal inputs of a voltage network provided in an integrated circuit;
• measuring a second current leakage at said signal connectors of said voltage network on said voltage network;
• comparing the first measured current leakage with said second measure current leakage;
• and
• sorting said chip based on said comparing.

A system for testing integrated circuits (IC) comprising:

• a voltage test device supporting an integrated circuit to be tested and having connections for inputting signals to and receiving signals from the integrated circuit;
• a voltage source providing a voltage signal to said test device for application at one or more signal inputs of a voltage domain provided in said integrated circuit, a voltage signal applied having a value less than a threshold transistor turn on voltage of a circuit's transistors within the domain;
• a current measurement device for measuring a current leakage at signal connectors of said voltage domain;
• and
• a computing device receiving said measured current leakage values, comparing the measured current leakage values with a pre-determined current limit specification based on an independent parameter characterizing said chip, and indicating a sorting of said integrated chip in response to said comparison, wherein said pre-determined current limit specification based on an independent parameter is prior obtained by:
• applying a voltage signal from an external voltage supply source to a power connector of a circuit having transistor devices, said circuit associated with the voltage domain, said applied voltage signal of a value less than a threshold transistor turn on voltage of the circuit's transistors;
• measuring a current leakage at said power connector of said voltage domain;
• measuring said independent parameter associated with said voltage domain that correlates to a transistor device strength or an integrated circuit chip performance;
• and
• using said computing device to:
• compare the measured current leakage of said voltage domain to the associated measured independent parameter;
• and
• create a current limit specification normalized to the independent parameter that correlates with the transistor device strength or said chip performance.

A system for testing integrated circuits (IC) comprising:

• a voltage test device supporting an integrated circuit to be tested and having connections for inputting signals to and receiving signals from the integrated circuit;
• a voltage source providing a first voltage signal to said test device for application at one or more signal inputs of a voltage network provided in said integrated circuit, said first voltage signal applied having a value less than a threshold transistor turn on voltage of a circuit's transistors;
• a current measurement device for measuring the first current leakage at signal connectors of said voltage network;
• said voltage source applying a high voltage stress to said one or more signal inputs of said voltage network that is a defect accelerating voltage;
• said voltage source further providing a second voltage signal of a value less than a threshold transistor turn on voltage of a circuit's transistors, at said one or more signal inputs of a voltage network provided in an integrated circuit;
• said current measurement device measuring a second current leakage value at signal connectors of said voltage network;
• a computer system for receiving said measured first current leakage values against said measured second current leakage values and comparing the measured first current leakage values against said measured second current leakage values;
• and
• sorting said chip based on said comparing.

The system as claimed 18, wherein said comparing performed by said computer system comprises:

• obtaining a difference between the first measured current leakage and second measured current leakage values;
• and
• comparing said difference to a pre-specified limit, wherein when said second measured current leakage is determined less than the first to exceed said limit, said sorting comprises one or more of:
• aborting production of said chip, disabling the whole or a portion of the voltage domain chip, or binning said chip for less reliable use.