Method for extracting flat-band voltage and threshold voltage of MOSFET (metal-oxide-semiconductor field effect transistor) based on current generation of grid-control drain electrode

Abstract

A method for extracting flat-band voltage and threshold voltage of an MOSFET (metal-oxide-semiconductor field effect transistor) based on current generation of a grid-control drain electrode belongs to the filed of micro electronic technique, is used for extracting VFB and VTH through the variation of grid-control generated current caused by the fact that a channel of the MOSFET changes from an accumulation region, an exhaustion region to a transoid region, and includes the following steps: an electrode at the source end of the MOSFET is hung in the air, a small drain voltage VD is exerted on the drain electrode, and the absolute valve of the VD is smaller than or equals to 0.2 V; the gate voltage VG is scanned, the channel changes from the accumulation region to the transoid region, and the grid-control generated current is measured under the drain bias VD; secondary partial differentiation operation for the obtained grid-control generated current curve IGD is performed to obtain the relation curve of the secondary derivative and the VG; the curve forms three peak value points, so as to obtain the peak value point corresponding to the rise edge and the peak value corresponding to the decline edge; the flat-band voltage VFB can be obtained through forming a vertical at the peak value point corresponding to the rise edge and enabling the vertical to be intersected with a grid voltage shaft; and the threshold voltage VTH can be obtained through forming a vertical at the peak value point corresponding to the decline edge and enabling the vertical to be intersected with the grid voltage shaft.

Description

Technical field: [0001] The invention relates to the technical field of microelectronics, and in particular to a method for extracting flat band voltage and threshold voltage of a device by using gate control to generate current in a MOSFET. Background technique: [0002] Flat band voltage in MOSFET (V IB ) Voltage, threshold voltage (V TH ) Are two very important electrical parameters. The flat band voltage reflects the charge in the gate oxide layer, generally test V FB It is tested by non-DC methods such as capacitor voltage (CV). The test method is to apply a pulse voltage of a certain frequency to the grid, and then measure the capacitance C between the grid linings. According to the comparison between the actual CV curve and the ideal CV curve, V FB . This method of testing requires a frequency generator, so the experimental equipment is complicated. In addition, many process parameters are required to obtain an ideal CV curve, and device users seldom can obtain these...

AI Technical Summary

Problems solved by technology

In summary, direct observation of the current generated by gating to determine V FB and V TH The traditional methods often cannot eliminate the artificial imprecision in the actual test

Images