Abstract
Previous investigations have reported substrate tilt and azimuthal (twist) orientations for bare, single-crystal gallium arsenide (GaAs) targets that control channeling-induced device parameter nonuniformities in variable scan angle (electrostatically scanned) ion implanters. However, those results were obtained using 2-in. (50.8 mm) and 3-in. (76.2 mm) diam GaAs substrates. Concern remains over whether the orientations reported will adequately control these nonuniformities when GaAs substrates with greater than 3-in.-diam are implanted. In this study implant profile and pinch-off voltage (Vp) dependence on twist orientation angle with a fixed 10° tilt along 150-mm-diam of bare GaAs targets are measured. Shottky capacitance-voltage measurements are employed to examine channeling-induced variations in Vp and electron concentration profiles for 29Si+ implantation at 100 and 60 keV. It is concluded that 10° tilt is not generally adequate to avoid the effects of planar channeling across the full diameter of bare GaAs wafers ≥100 mm. An analysis employing a stereographic projection, combined with data from this investigation, indicates that, in order to obtain optimum control over implant depth profile variations across large diameter (≥100 mm) GaAs wafers implanted with electrostatic scanning, the use of tilt angles ≳10° (perhaps 12°–15°) may be required.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
