Extraction method for of threshold voltage of MOSFET on the basis of drain control generation current

Abstract

The present invention discloses an extraction method for of a threshold voltage of MOSFET on the basis of a drain control generation current. The extraction method provided by the invention comprise: a channel inversion layer is located in the inversion state through adoption of fixation of large gate voltage VG, and at the same time a drain voltage VD is scanned to obtain a curve of a drain control generation current IDC; and when the drain voltage VD is increased up to allow a channel at the edge of the drain end to start the occurrence of exhaustion, the IDC curve is beginning to rapidly increase and turns up a peak, and the point of abrupt change is just a difference of a gate voltage and the drain voltage with respect to a critical point or a turning point inverting up to exhaustion, namely the threshold voltage VT. An accurate, simple and fast test method of MOSFET is provided by the invention. Because the curve presents an abrupt change, the drain voltage point with respect to the turning point inverting up to exhaustion may be easier observed, so that the man-made observation error may be avoided; the operation of obtaining a threshold voltage is simple; and the measurement is fast, and a direct current test is only needed.

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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