Recent Advancement in Noncontact Wafer Level Electrical Characterization for WBG Technologies

Abstract:

A breakthrough high throughput WBG semiconductor dopant monitoring method has recently been introduced based on the novel concept of sweeping the electrical bias by near UV illumination-induced photoneutralization of corona charge. As originally discovered for 4H-SiC, the doping determination can be realized using the value of the photoneutralization time constant. In the present work this procedure is tested for β-Ga₂O₃ with a larger energy gap of 4.8eV, using a correspondingly deeper UV range. Such deep UV application to the AlGaN/GaN HEMT structure resulted in the development of a new measurement principle capable of increasing the HEMT wafer measurement throughput 10 times compared to previous corona noncontact C-V metrology. The new principle involves a linear illumination-induced corona charge bias sweep. Combined with surface voltage monitoring, it provides a means for fast and precise determination of the pinch-off voltage, V_P, the AlGaN electrical thickness, and the 2D electron gas density.

• Periodical: Materials Science Forum (Volume 1157)
• Pages: 49-56
• DOI: https://doi.org/10.4028/p-qU8rgR
• Online since: September 2025
• Authors: Marshall Wilson*, Alexandre Savtchouk, Liliana Gutierrez, Carlos Almeida, Jacek Lagowski
• Keywords: Corona, Doping, Ga₂O₃, HEMT, Non-Contact Characterization, SiC

References

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DOI: 10.1149/2.0291711jss

[3] M. Wilson, J. Lagowski, C. Almeida, B. Schrayer, and A. Savtchouk, "Semiconductor doping characterization method using photoneutralization time constant of corona surface charge", US Patent Granted US12027430B1, Publication Date July 2, 2024.

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DOI: 10.1002/pssa.202100416

[6] M. Wilson, J. Lagowski, I. Shekerov, C. Almeida, B. Schrayer, L. Gutierrez and A. Wincukiewicz, "Wide Bandgap Semiconductor Characterization Based on Capacitance Characteristics Acquired Using Corona Surface Charge Neutralization by UV Radiation Pulses," US Patent Pending 02695-0058001, submitted May 2025.