Precise beam incidence angle control on the VIISta 810HP

The VIISta 810HP ion implanter has precise control over the angle of incidence of the ion beam to the wafer. The machine is capable of delivering the beam to within ±0.2° of the desired tilt angle. A brief overview of the hardware and software used to achieve this is given in the paper. Experiments have been performed to verify this capability. <100> silicon wafers were implanted at a variety of incidence angles in order to perform a coarse alignment of the wafer platen to the beam using sheet resistance and Thermawave Thermaprobe measurements. Following these implants another series of implants was performed to develop a SIMS calibration curve for implant angle variations in tenths of a degree. The resulting data show both that the calibration technique is viable and that the VIISta 810HP has stable and repeatable control over the beam incidence angle.