Metal oxide semiconductor field effect transistor on-resistance measuring method

Abstract

The invention relates to a metal oxide semiconductor field effect transistor on-resistance measuring method which comprises the following steps: sucking the back surface of a wafer through a chuck; connecting a low-potential excitation line and a low-potential detection line in a Kelvin test method to a source electrode of a MOS transistor to be tested, connecting a first high-potential excitation line and a first high-potential detection line in the Kelvin test method to a grid electrode of the MOS transistor to be tested, selecting another MOS transistor on the wafer as an auxiliary transistor, connecting a second high-potential excitation line in the Kelvin test method to the chuck, and connecting a second high-potential detection line in the Kelvin test method to a source electrode of the auxiliary transistor; and adding a break-over voltage between a grid electrode and the source electrode of the auxiliary transistor to enable the auxiliary transistor to be in an on state, powering on an on-resistance measuring circuit and measuring the on-resistance of the MOS transistor to be tested. Through a die compensation method, real Kelvin connection is realized, so that on-resistance of the MOS transistor can be measured stably and accurately.

Description

technical field [0001] The invention relates to the measurement of resistance, in particular to a method for measuring the on-resistance of metal oxide semiconductor field effect transistors. Background technique [0002] Power control and power conversion is an important field where metal oxide semiconductor field effect transistors (MOSFETs, MOS tubes for short) are widely used. In such applications, MOS tubes are usually used as switches, and on-resistance is one of the most critical parameters. , which directly affects the stability of the application circuit. Therefore, the on-resistance (R dson ) Accurate measurement has become the focus of MOS tube testing. [0003] With the continuous introduction of new MOSFETs, the resistance value of the on-resistance is getting smaller and smaller, and products on the order of milliohms are already common. In order to accurately measure the tiny conduction resistance, the Kelvin method is usually used for resistance testing. ...

AI Technical Summary

Problems solved by technology

[0004] However, due to the structural limitations of the wafer, there are only two PADs on the front of the actual wafer, the gate and the source, and the drain is on the back of the wafer.

Since the entire wafer is adsorbed on the chuck of the probe station during the test, and the back of the wafer is blocked by the chuck, the Kelvin double wire can only be connected to the edge of the chuck, and the true Kelvin connection cannot be realized, resulting in inaccurate test values.

At the same time, since the contact on the back of the wafer changes randomly, it also brings about instability in the test.

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