Wafer-level burn-in oven

Abstract

A system for burn-in testing of integrated circuits and semiconductors at the wafer level and apparatus and method utilizing the system. The cascading heat control system of the invention has connected first and second heat transfer circuits to regulate the temperature of and the environment around semiconductor wafers under test. A low temperature gas is circulated, as a heat transfer gas, through the cascading heat control system. The heat transfer gas serves as a heat transfer medium and provides a low dew point environment, or both a low dew point and low oxidation environment, within the system. At least one wafer chuck incorporating a heat exchanger, or a series of such wafer chucks, and containing a semiconductors for testing is connected to the cascading heat control system through the heat exchanger. In the apparatus, a burn-in oven, the wafer chuck or series of wafer chucks are contained within a chamber environment. The first heat transfer circuit circulates heat transfer gas to the wafer chuck and a second heat transfer circuit circulate heat transfer gas within and through the chamber environment. In the method of the invention, heat transfer gas is circulated through the circuits and may be heated to a target temperature. Once at the target temperature, test signals are provided to the semiconductor wafers under test and cascading heat control system regulates the temperature and environment within the apparatus.