A wafer shielding chamber assembly for a semiconductor wafer probe station that minimizes the volume of space about the semiconductor wafer so as to minimize air currents about the wafer. The chamber is formed by positioning an annular spacer ring onto the annular periphery of the wafer chuck....http://www.google.de/patents/US5835997?utm_source=gb-gplus-sharePatent US5835997 - Wafer shielding chamber for probe station
