The anomalous threshold voltage shift of N- and P-MOSFET under flow and reflow of BPSG film with RTA and/or furnace

Different post oxide annealing technologies, i.e. furnace and/or RTA were done in borophosphosilicate glass (BPSG) films under flow and reflow. It is found that the threshold voltage shift is apparent in P-MOSFET but small in N-MOSFET for a device with RTA reflow. Base on the charge pumping measurement, the donor-type interface states generated by RTA reflow process are supposed to play a major role in this shift. The authors explain the mechanism of RTA induced donor-like interface states in detail.<
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