Effective channel length determination using punchthrough voltage

A new method for effective channel length (L/sub eff/) determination using the punchthrough phenomenon in short-channel MOSFETs is proposed. The punchthrough voltage of short-channel MOSFETs is a strong function of L/sub eff/. Single doped drain and lightly doped drain (LDD) MOSFETs were evaluated by means of this method, which is called the punchthrough method. The punchthrough method gave excellent results in terms of relative measurement accuracy, reproducibility, and resolution. The L/sub eff/ determined by the punchthrough method does not depend on the parasitical resistance of the source and drain region. Because of its high resolution and simplicity, this punchthrough method can be very useful for Leff monitoring in manufacturing.<
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