CN-115902562-B - Interface defect detection method and wafer detection method

CN115902562BCN 115902562 BCN115902562 BCN 115902562BCN-115902562-B

Abstract

The application belongs to the technical field of semiconductors, and provides an interface defect detection method and a wafer detection method, wherein the interface defect detection method applies a horizontal static magnetic field to a device with power to be detected to change the spin direction of electrons in a defect energy level, the spin direction is downward, the spin direction of electrons in the defect energy level is turned over after a radio frequency magnetic field is applied, the direction is upward, so that the pairing action of electrons originally paired with the defect energy level in the conduction band is forbidden, at the moment, the electrons from the conduction band fall into the valence band and are recombined with holes in the valence band to form leakage current, and then the interface defect density is detected by detecting the size of the leakage current.

Inventors

CHEN TAO
HUANG HUIQIN

Assignees

天狼芯半导体(成都)有限公司

Dates

Publication Date: 20260505
Application Date: 20221114

Claims (9)

1. The interface defect detection method is applied to a power device to be detected, and is characterized in that a drain electrode of the power device to be detected is connected with a power supply, a source electrode of the power device to be detected is grounded, a grid electrode of the power device to be detected is suspended, and the interface defect detection method comprises the following steps: applying a horizontal static magnetic field to the power device to be tested, wherein the horizontal static magnetic field is used for adjusting the spin direction of electrons in a defect energy level; applying a radio frequency magnetic field above the grid electrode of the power device to be tested, wherein the radio frequency magnetic field is used for turning over the spin direction of electrons in the defect energy level so that electrons from a conduction band move into holes in a valence band to form leakage current; detecting leakage current of the power device to be tested, and determining interface defect density of the power device to be tested according to the leakage current; The method for applying the horizontal static magnetic field to the power device to be tested comprises the steps of respectively arranging a first magnet and a second magnet on two sides of a source electrode and a drain electrode of the power device to be tested, wherein the first magnet and the second magnet are used for generating the horizontal static magnetic field.
2. The interface defect detection method of claim 1, wherein the applying a radio frequency magnetic field over the gate of the power device under test further comprises: And a radio frequency coil is arranged above the grid electrode of the power device to be tested, and the radio frequency coil generates the radio frequency magnetic field when being electrified.
3. The interface defect detection method of claim 2, wherein the radio frequency coil is centered over the gate.
4. The interface defect detection method of claim 2, wherein the disposing a radio frequency coil above the gate of the power device under test further comprises: And a magnetic core unit is arranged at the center of the radio frequency coil and used for increasing the intensity of the radio frequency magnetic field.
5. The interface defect detection method of any of claims 1-4, wherein applying a radio frequency magnetic field over the gate of the power device under test comprises: The intensity of the radio frequency magnetic field is adjusted so that the spin direction of electrons in the defect energy level is inverted.
6. The interface defect detection method of any one of claims 1-4, wherein the first magnet and the second magnet are symmetrically disposed.
7. The interface defect detection method of claim 1, wherein applying a horizontal static magnetic field to the power device under test comprises: and placing the power device to be tested in a sealing cavity, and respectively arranging a first magnet and a second magnet on two sides of a source electrode and a drain electrode of the power device to be tested.
8. The method for detecting an interface defect according to claim 1, wherein detecting the leakage current of the power device to be detected, and determining the size of the interface defect of the power device to be detected according to the size of the leakage current comprises: comparing the leakage current with a preset mapping table, and determining the interface defect density of the power device to be tested according to a comparison result.
9. A method for inspecting a wafer, wherein the wafer includes a plurality of power devices and at least one power device to be inspected, and the power device to be inspected is inspected for defect density by using the interface defect inspection method according to any one of claims 1 to 8.

Description

Interface defect detection method and wafer detection method Technical Field The application belongs to the technical field of semiconductors, and particularly relates to an interface defect detection method and a wafer detection method. Background Reliability assessment of power device performance is an important part of the integrated circuit process development process. However, reliability evaluation of Gate Oxide (Gate Oxide) in a power device is an important item in the front section, mainly for evaluating the performance of the front section dielectric material. Many processes in the integrated circuit fabrication process may affect the upper and lower interfaces of the gate dielectric layer, thereby affecting the TDDB (TIME DEPENDENT DIELECTRIC Breakdown ) of the gate dielectric layer, exhibiting a polarity dependence. Therefore, how to effectively characterize the defect density of the upper and lower interfaces of the gate dielectric layer is very important. Through long-time research and development, the current method for representing the interface defect density based on the parallel conductance method is mainly applied to Si-based MOS devices, but the method itself often has a relatively strict application range and conditions, such as a requirement for low leakage current of the devices. Since the AlGaN/GaN HEMT is a device with higher leakage current, the results obtained are clearly inaccurate if the interface defect density of the AlGaN/GaN HEMT is simply characterized by the above method. In addition, the Si material and the GaN material have larger difference in the effective state density of conduction band, the forbidden band width, the interface defect density and the like, so the reliability of the result obtained by adopting the parallel conductance method is doubtful. Therefore, the existing interface defect detection method of the power device has the problems of small application range and inaccurate detection result. Disclosure of Invention In order to solve the technical problems, the embodiment of the application provides an interface defect detection method and a wafer detection method, which aim to solve the problems of small application range and inaccurate detection result of the interface defect detection method of the traditional power device. The embodiment of the application provides an interface defect detection method which is applied to a power device to be detected, wherein a drain electrode of the power device to be detected is connected with a power supply, a source electrode of the power device to be detected is grounded, a grid electrode of the power device to be detected is suspended, and the interface defect detection method comprises the following steps: applying a horizontal static magnetic field to the power device to be tested, wherein the horizontal static magnetic field is used for adjusting the spin direction of electrons in a defect energy level; applying a radio frequency magnetic field above the grid electrode of the power device to be tested, wherein the radio frequency magnetic field is used for turning over the spin direction of electrons in the defect energy level so that electrons from a conduction band move into holes in a valence band to form leakage current; detecting leakage current of the power device to be tested, and determining interface defect density of the power device to be tested according to the leakage current. In one embodiment, before the applying the radio frequency magnetic field over the gate of the power device under test, the method further includes: And a radio frequency coil is arranged above the grid electrode of the power device to be tested, and the radio frequency coil generates the radio frequency magnetic field when being electrified. In one embodiment, the center of the radio frequency coil is located above the gate. In one embodiment, the disposing a radio frequency coil above the gate of the power device under test further includes: And a magnetic core unit is arranged at the center of the radio frequency coil and used for increasing the intensity of the radio frequency magnetic field. In one embodiment, the applying the radio frequency magnetic field over the gate of the power device under test includes: The intensity of the radio frequency magnetic field is adjusted so that the spin direction of electrons in the defect energy level is inverted. In one embodiment, the applying a horizontal static magnetic field to the power device under test includes: And a first magnet and a second magnet are respectively arranged at two sides of a source electrode and a drain electrode of the power device to be tested, and the first magnet and the second magnet are used for generating the horizontal static magnetic field. In one embodiment, the first magnet and the second magnet are symmetrically disposed. In one embodiment, the applying a horizontal static magnetic field to the power device under test includes: and placing t