Test method of metal oxide semiconductor field-effect transistor threshold voltage

Abstract

The present invention provides a method for testing a threshold voltage of a field effect transistor of the metal oxide semiconductor. The back substrate of the SOI-CMOS circuit is connected with an earth potential or an electric power potential, wherein, when the threshold voltage of the NMOS is tested, the back substrate is connected with the earth potential; and when the threshold voltage of the PMOS is tested, the back substrate is connected with the negative electric power potential. When the threshold voltage of the NMOS is tested, the back substrate is connected to the electric power potential; and when the threshold voltage of PMOS is tested, the back substrate is connected to the earth potential. The invention fixes the back substrate of SOI-CMOS circuit on a certain potential, and the operations of N, PMOS devices in SOI circuit are in back grid biases which are totally indifferent. Therefore, the condition for singly characterize the threshold voltage of N, PMOS should be altered correspondingly, and in this way the threshold voltage can be correctly recognized and controlled in order to guarantee the normal operation of SOI circuit.

Description

technical field [0001] The invention relates to an SOI-CMOS semiconductor integrated circuit, in particular to a substrate connection method during circuit packaging and an N-type or P-type metal oxide semiconductor field effect transistor (Metallic oxide semiconductor field effect transistor, NMOSEFT) in an SOI-CMOS semiconductor integrated circuit , PMOSEFT) threshold voltage test characterization method. Background technique [0002] SOI (Silicon-On-Insulator) technology refers to the fabrication of devices and circuits on a silicon film on an insulating layer (Box) (see Figure 1). Due to the existence of the buried oxide layer (Box), complete dielectric isolation is realized between devices, so the SOI-CMOS integrated circuit essentially avoids the latch-up effect of the bulk silicon CMOS circuit. In addition, the short channel effect of SOI devices is small, and shallow junctions can be formed naturally, and the leakage current is small. The small junction area result...

AI Technical Summary

Problems solved by technology

Generally speaking, the threshold voltage of the device will be inaccurate, or the sub-threshold leakage of the device will occur, resulting in excessive power consumption of the overall circuit.

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