Time-dependent dielectric breakdown of recessed AlGaN/GaN-on-Si MOS-HFETs with PECVD SiO2 gate oxide

• Published in: Vacuum 2018-09, Vol.155, p.428-433
• Main Authors: Kim, Hyun-Seop, Eom, Su-Keun, Seo, Kwang-Seok, Kim, Hyungtak, Cha, Ho-Young
• Format: Article
• Language: English
• Subjects: AlGaN/GaN MOS-HFETs; Charge density; Flat-band voltage; PECVD; Reliability; SiO2; TDDB
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2018.06.043

This paper reports the first-time evaluation of the time-dependent dielectric breakdown of recessed AlGaN/GaN-on-Si metal-oxide-semiconductor heterostructure field-effect transistors (MOS-HFETs) with plasma enhanced chemical vapor deposition (PECVD) SiO2 gate oxide. The interface fixed charge density and oxide bulk charge density extracted from the flat-band voltage characteristics were 2.7 × 1011 ± 6.54 × 1010 cm−2 and -9.71 × 1017 ± 5.18 × 1016 cm−3, respectively. The time dependent dielectric breakdown (TDDB) characteristics exhibited longer lifetime estimation as the SiO2 thickness increased. The excellent reliability of the PECVD SiO2 film was validated for use as the gate oxide of recessed AlGaN/GaN MOS-HFET. •We reports the TDDB characteristics of recessed AlGaN/GaN-on-Si MOS-HFETs with PECVD SiO2 gate oxide for the first time.•We observed that the PECVD SiO2 films had negative net bulk charges.•The interface fixed charge density and oxide bulk charge density were 2.4 × 1011 cm−2 and -9.71 × 1017 cm−3, respectively.•The TDDB characteristics exhibited longer lifetime estimation as the SiO2 thickness increased.