Experimental Study and Modeling of the gm-I Dependence of Long-Channel MOSFETs

This paper describes an experimental study and modeling of the current-transconductance dependence of the ALD1106 and ALD1107 arrays. The study tests the hypothesis that the I-g_m dependence of these 7.8 μm MOSFETs conforms to the Advanced Compact Model (ACM). Results from performed measurements, however, do not support this expectation. Despite the relatively large length, both ALD1106 and ALD1107 show sufficiently pronounced `short-channel' effects to render the ACM inadequate. As a byproduct of this effort, we confirmed the modified ACM equation. With an m factor of approximately 0.6, it captures the I-g_m dependence quite well. The paper also introduces several formulas and procedures for I-g_m model extraction and tuning. These are not specific to the ALD transistor family and can be applied to MOSFETs with different physical size and electrical performance.