What is High-Temperature Operating Life or HTOL?

High Temperature Operating Life (HTOL) is a test, the is used to determine the reliability of an IC or DUT in high-temperature conditions over an extended period of time. During this test, the IC or device is placed in a high-temperature environment and is subjected to high voltage and dynamic operation for a predefined period of time. This causes increased electrical stress and expedites any potential failures that a device might experience over its lifetime operating under normal conditions.

All semiconductor devices usually have a lifespan of at least a few years. Due to this it is not possible to test device over its entire expected life span. Applying additional stress enhances or accelerates potential failure mechanisms, and helps identify the root cause. This assists engineers identify potential failure today that might occur over an extended period of time.

In semiconductor device reliability testing, accelerants like temperature, humidity, voltage, and current are put to use. In most cases, the accelerated testing does not change the physics of the failure, but it does alter the fault timeline.