Infineon Technologies Richmond, LP

Michael Wright

Frederico Garza

Karl Peterson

A device to implant impurities into a semiconductor wafer has a process chamber having a wall, a pressure compensation unit, a disk to support a plurality of semiconductor wafers within the process chamber. The disk has a radially extending slot arranged among the wafers. A beam gun is positioned within the process chamber to shoot an ion beam at the semiconductor wafers. A cryo pump minimizes the pressure within the process chamber. A first ion gauge is positioned between the process chamber and the cryo pump. A second ion gauge extends through the wall of the process chamber. A switching device selectively connects the first or second ion gauge to the pressure compensation unit. A faraday receives ions from the ion gun filter after the ions travel through the slot in the disk. A current meter counts the number of electrons flowing to the disk faraday to neutralize the ions.

Utilization of an ion gauge in the process chamber of a semiconductor ion implanter

A process uses pressure changes and a pressure compensation factor to estimate the rate at which neutral atoms are implanted. While implanting a first wafer using a first pressure compensation factor, the rate at which ions are implanted is determined. The first wafer is moved radially with respect to an ion beam while implanting ions into the first wafer so as to achieve a uniform total dose based on the rate at which ions are implanted and the estimated rate at which neutral atoms are implanted. The pressure is determined while implanting the first wafer, determining the pressure. A second pressure compensation factor is selected, that would have achieved a uniform rate of implanted ions plus implanted neutral atoms across a surface of the first wafer. The second pressure compensation factor is different from the first pressure compensation factor. The second pressure compensation factor is used to implant a second wafer. The second wafer is tested by forming a sheet resistance contour map. If the sheet resistant contour map shows uniform resistance across the wafer, the second pressure compensation factor is used to implant wafers subsequent to the second wafer.

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Richmond, VA, United States of America

Michael Wright