Gate Oxide Formation under Mild Conditions for Scanning Capacitance Microscopy
Duncan McBride, Joseph Kopanski
Scanning Capacitance Microscopy (SCM) can be used to measure doping density in silicon with a spatial resolution of about 10 nm. In order to make such measurements on fabricated devices, the device must be cross-sectioned, and an oxide sufficient to form a MOS device with the SCM probe tip must be grown on the cut face without affecting the device structure. Thus thermal oxidation under conditions usually employed to grow the gate oxide (900C) cannot be used. We have systematically investigated oxide growth on silicon under mild conditions. An oxide sufficient for SCM can be grown thermally on a clean, polished silicon surface at a temperature of 300 - 350:C. In addition, such an oxide can be made near room temperature under intense ultraviolet light in the presence of ozone. SCM measurements using such an oxide show stable flatband voltages and breakdown above 3 Volts. Oxide thickness, measured ellipsometrically, is 2.0 1 0.2 nm.
Characterization and Metrology for ULSI Technology
and Kopanski, J.
Gate Oxide Formation under Mild Conditions for Scanning Capacitance Microscopy, Characterization and Metrology for ULSI Technology, Gaithersburg, MD, USA
(Accessed February 27, 2024)