It features it that is big that the voltage and an electric current to handle
with a semiconductor converting control and electricity such as a motor or
the lighting with the power semiconductor is big. There are the kinds
such as a diode or the transistor, and materials such as SiC or GaN are researched
and developed recently by Si.
The evaluation object is introduced to many divergences such as confirmation and
trouble analysis of the device structure, Non Destructive Inspection
in the packed state commencing with the defect included in a board and the film.
Crystal defect evaluation of the SiC power device by PL, the TEM
By the PL (photoluminescence) mapping, the identification of the crystal defect position is possible from the luminescent point.
Furthermore, I can arrest a lamination defect by performing high-resolution STEM observation (image of HAADF-STEM) at an equivalence point. In this example, I investigated commercial SiC power device using PL mapping and STEM observation.
After pinpointing the laminated defect position by PL mapping, I performed FIB processing about a defect edge minute and carried out section STEM observation.
Sample summary
Result of analysis
The stacking fault position was confirmed by PL mapping.
FIB processing was performed on the identified defect edge portion, and cross-section observation was performed.
Bright-field-STEM image
A defect was confirmed at a position of 4.6 μm from the device surface.
A high-resolution HAADF-STEM image of the defect part was acquired and From the shift, it was confirmed that it was SSF * 1 (3,1).
Roughness evaluation of trench sidewall of SiC MOSFET
In recent years, SiC has attracted attention as a material for high voltage devices. The Trench MOSFET structure is required for high integration of the device, and its application to SiC devices is being developed.
Since the channel region of the Trench MOSFET structure is the sidewall of the trench, the flatness of the trench sidewall plays a role in device reliability. This document presents an example of quantitatively evaluating the roughness of the trench sidewall of a SiC Trench MOSFET using an AFM (atomic force microscope).
Breakdown observation of 600V withstand voltage SiC Schottky Diode
By using a high voltage power supply (up to 2000V can be applied), it is possible to generate a breakdown even for a diode with a high breakdown voltage.
In this example, a breakdown was generated by operating a 600V SiC Schottky Diode and applying a high voltage in the reverse direction. In this section, we will introduce an example of identifying the location of breakdown current by observing the emission microscope after removing the cathode electrode by polishing. A commercially available product is used for the measurement.
Evaluation example of in-plane distribution of resistance value by SRA
In SRA, in addition to the concentration distribution of the carrier in the depth direction, it is also possible to evaluate the in-plane distribution of the resistance value on the sample surface or specified depth.
As an example, we introduce a case in which a commercially available Si-IGBT chip is disassembled and the carrier concentration distribution evaluation of the lifetime killer in the depth direction and the in-plane distribution evaluation of the resistance value at the lifetime killer irradiation depth are performed by SRA. To do.
Non-destructive 3D structure observation of SiC Trench MOSFET discrete package
In the investigation of other companies' products and inspection of abnormal products, it is necessary to first investigate the internal structure. With X-ray CT, it is possible to non-destructively acquire a transmission image inside the sample and construct it three-dimensionally. This document introduces an example of observing a discrete package equipped with a SiC chip by X-ray CT as part of a product survey.
After confirming the structure by X-ray CT, we propose the physical analysis (destruction analysis) carried out by MST.
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