Programmable semiconductor wafer for sensing, recording and retrieving

Abstract

A semiconductor wafer is provided for sensing and recording processing conditions to which the wafer is exposed. The wafer can also write the recorded processing conditions to an external output device connectable to the wafer. The wafer includes a plurality of regions spaced across the wafer, and at least one sensor placed within each region. The sensor can sense a single processing condition such as, e.g., pressure, temperature, fluidic flow rate, or gas composition. If more than one processing condition is to be measured, then more than one sensor can be placed in each region to provide a sensed reading across the entire wafer surface necessary for gradient measurements. The wafer further includes signal acquisition/conditioning circuit which receives analog signals from each of the sensors placed upon the wafer and converts the analog signals to corresponding digital signals. Digital signals can then be stored within and processed by a processor also formed within the wafer. The semiconductor wafer further includes input/output probe pads which receive external input to the wafer circuitry and output stored information from the circuitry.