A method of generating current extraction threshold voltage of mosfet based on leakage control

Abstract

The invention discloses a method for extracting the threshold voltage of a MOSFET based on the current generated by leakage control, using a fixed larger gate voltage VG to make the channel inversion layer in an inversion state, and scanning the drain voltage VD at the same time to obtain the current IDC curve generated by leakage control , when the drain voltage increases to such an extent that the channel at the edge of the drain begins to deplete, the IDC curve begins to increase rapidly, and the curve appears a sharp peak, and this abrupt point corresponds to the critical point or turning point from inversion to depletion The difference between the gate voltage and the drain voltage is the threshold voltage VT. The present invention provides an accurate, simple and fast test method for the measurement of MOSFET; since the curve presents a sudden change, it is easier to observe the leakage voltage point corresponding to the transition from inversion to depletion, avoiding the error of human observation; obtaining The calculation of the threshold voltage is simple; the final measurement is fast and only needs a DC test.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to a method for extracting a threshold voltage of a MOSFET based on leakage control generated current. Background technique [0002] MOSFET threshold voltage V T Is an important parameter in the device, which is closely related to the fixed charge in the gate oxide layer, the interface charge, and the work function difference between the substrate and the gate electrode material. Therefore, the measurement accuracy of the threshold voltage is very easily affected by the measurement method. The traditional measurement method is: at the drain voltage V D At about 50mV, the test gate voltage V G - Leakage current I D curve, and then extract the I D The maximum transconductance point of the curve corresponds to the gate voltage V G value, from the V G value corresponding to I D Points on the curve make a tangent, and the tangent intersects with V G The corresponding ga...

AI Technical Summary

Problems solved by technology

The characteristic of this method is that it is more accurate, but it is more complicated for the test procedure.

Another method is gate control based on gate control drain to generate current to extract MOSFET flat-band voltage and threshold voltage. This method is characterized by DC testing, but it also needs to use more complex differential in the process of extracting flat-band voltage. operation

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