Chuck temperature control equipment null for semiconductor wafer test

摘要

PURPOSE: To provide a wafer chuck temp. control system for use in a semiconductor wafer testing equipment. ;CONSTITUTION: A wafer chuck 1 is divided in regions 2 of temp. sensor cooling elements, corresponding to chip position regions of an undiced wafer under test. Computer-controlled scan over the sensors determines which regions house heat sources (in the chip under test), which are then selected for connection to a closed-loop temp. control feedback servo. Means is provided for introducing a He gas interface between the wafer and chuck, when the wafer is vacuum-sat to the chuck to flow He in annular trenches which are formed into the inner surface of the chuck. Specified He gas flow rate is held to keep the vacuum retention and optimize the thermal resistance of a wafer chuck interface.;COPYRIGHT: (C)1994,JPO