Method for implanter angle verification and calibration

Abstract

Methods () are described for calibrating the implantation angle of an ion implanter utilized in the manufacture of semiconductor products. One method () includes implanting () phosphorous ions into a pilot wafer held by a wafer platen held at a starting implantation angle in the ion implanter. The phosphorous implantation into a p-doped substrate of the pilot or blank wafer, for example, forms a semiconductive sheet. The method () then includes changing the implantation angle (), and implanting another wafer () with phosphorous ions. The angle changing () and implanting () of other wafers continues in this manner until all wafers or angles are implanted () as desired. The phosphorous implanted wafers are then measured () with a four-point probe, for example, to obtain the sheet resistance of all the implanted wafers. The difference between the sheet resistances of the wafers at each corresponding implant angle is then obtained () to determine a functional relationship between the sheet resistance and the implantation angle. Finally, the functional relationship is then used to calibrate () the implantation angle of the implanter. For example, the lowest sheet resistance of the functional relationship may be determined, the relationship normalized to the lowest sheet resistance, then a zero degree implantation angle of the implanter is calibrated to to coincide with the lowest sheet resistance measurement.