Method for testing semiconductor devices

A method for testing integrated circuit semiconductor devices comprising the steps of;

• a) providing a wafer containing a plurality of integrated semiconductor devices;
• b) determining functionality of said integrated semiconductor devices at a predetermined set of operating conditions;
• c) segregating said integrated semiconductor devices on said wafer by measuring operating speed of said devices;
• d) applying a stress test to said devices wherein test conditions of said stress test are adjusted based on said segregation parameter measurements of said devices by applying a first voltage at a value higher than the device normal operating voltage to said devices with a first measured operational speed, and a second voltage at a value lower than said first voltage to said devices with a second measured operational speed, said fast operational speed being less than said second operational speed;
• e) determining functionality of said devices at nominal operating conditions after said stress test;
• and,
• f) classifying said devices as failed if said devices do not function properly after said stress test.

A method for testing integrated circuit semiconductor devices comprising the steps of:

• a) providing a wafer containing a plurality of integrated semiconductor devices which includes n-type and p-type field effect transistors;
• b) determining functionality of said integrated semiconductor devices at a predetermined set of operating conditions;
• c) segregating said integrated semiconductor devices on said wafer by measuring operating speed of said devices comprises the steps of:
• i) measuring drain-to-source current for said n-type and p-type field effect transistors;
• ii) determining a drain-to-source current sum by summing the value of said n-type drain-to-source current with the absolute value of said p-type drain-to-source current;
• iii) determining a device ISUM value by dividing said drain-to-source current sum by said gate channel width of said device;
• and
• iv) segregating said devices based on said ISUM value wherein said devices with lower ISUM values correspond to slower operational speeds and devices with higher ISUM values correspond to faster operation speeds;
• d) applying a stress test to said devices wherein test conditions of said stress test are adjusted based on said segregation parameter measurement of said devices;
• e) determining functionality of said devices at nominal operating conditions after said stress test;
• and,
• f) classifying said devices as failed if said dices do not function properly after said stress test.