In-wafer reliability screening method for GaN HEMT (High Electron Mobility Transistor) device

Abstract

The invention discloses an in-wafer reliability screening method for a GaN HEMT (High Electron Mobility Transistor) device. The in-wafer reliability screening method is characterized by comprising the following steps that: firstly, in-wafer electroluminescence spectrum testing platform is established, a GaN heterojunction HEMT device wafer is placed on a probe platform in a darkroom, and then probes are respectively pressed on a grid electrode, a source electrode and a leakage electrode; and then, the source electrode is grounded, certain forward bias is applied to the leakage electrode, backward bias Vgs, which changes from pinch-off voltage Vp to 0V, is applied to the grid electrode, a change relationship between the luminous intensity of a GaN heterojunction HEMT device and grid voltage is tested by virtue of a spectrum testing system, the luminescence spectrum of the device is tested under the adopted bias point Vgsm with the largest luminous intensity, and then the spectrum is analyzed to evaluate the reliability of the device. The in-wafer reliability screening method has the advantages that in-wafer screening can be realized; a series of reliability screening preparation procedures, such as scribing and packaging, is eliminated without long-time electric stress; and the reliability screening time is shortened, costs are saved, and work efficiency is improved.

Description

technical field [0001] The invention relates to an on-chip screening method for the reliability of GaN HEMT devices, which is a method for screening the reliability of GaN HEMT devices by utilizing the GaN HEMT high-field luminescent phenomenon, and belongs to the technical field of semiconductor devices. Background technique [0002] GaN HEMT devices have experienced nearly two decades of development, and the microwave performance of the device has been gradually improved and approached its theoretical limit. However, because it is mostly used in the microwave high-power field, the device often works at a very high drain-source bias voltage. The hot electrons generated under high electric field will degrade the characteristics of HEMT devices, and the resulting reliability problems have always hindered the development and wide application of GaN HEMTs. Therefore, the study of GaN HEMT failure mechanism has always been a very important link in the field of GaN device researc...

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Problems solved by technology

[0002] GaN HEMT devices have experienced nearly two decades of development, and the microwave performance of the device has been gradually improved and approached its theoretical limit. However, because it is mostly used in the microwave high-power field, the device often works at a very high drain-source bias voltage. The hot electrons generated under high electric field will degrade the characteristics of HEMT devices, and the resulting reliability problems have hindered the development and wide application of GaN HEMTs.

Studies have found that the strong electric field peaks on the edge of the GaN HEMT gate electrode near the drain cause the electrons on the gate electrode to tunnel and inject to the surface of the barrier layer, and the leakage current between the gate and the drain is generated through the hopping conductance between surface defects. Charge the surface traps, reduce the electron gas concentration in the lower channel, cause a decrease in drain current and transconductance, and degrade device performance

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