Test System Control Technique Detecting Potential Short Circuit Defects by Use of a Voltage Screen
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
Redeposited, oxidized aluminum from the lift-off process can become a short between device conductors if a high voltage breaks the oxide down and welds the aluminum in place. By programming a device tester appropriately, a high-voltage screen is applied to silicon gate devices, thereby inducing this type of failure at final test. These failures otherwise would occur in the field and become reliability detractors. The device tester is programmed to perform the voltage screen function prior to performing normal tests. The high voltage condition is applied to the device under test for a time duration short enough that device life is not affected, but long enough to exceed time of high voltage application in normal use. The high voltage is applied to the highest possible number of switching gates on the device.