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Surface Preconditioning and Postmetallization Anneal Improving Interface Properties and V th Stability under Positive Gate Bias Stress in AlGaN/GaN MIS‐HEMTs
Author(s) -
Calzolaro Anthony,
Szabó Nadine,
Großer Andreas,
Gärtner Jan,
Mikolajick Thomas,
Wachowiak Andre
Publication year - 2021
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.202000585
Subject(s) - materials science , optoelectronics , threshold voltage , gate dielectric , transistor , dielectric , capacitance , analytical chemistry (journal) , voltage , electrical engineering , chemistry , electrode , engineering , chromatography
Trap states at the dielectric/GaN interface of AlGaN/GaN‐based metal–insulator–semiconductor high electron mobility transistors (MIS‐HEMTs) can cause threshold voltage ( V th ) instability especially under positive gate bias stress. Herein, the influence of O 2 plasma surface preconditioning (SPC) before the atomic layer deposition of the Al 2 O 3 gate dielectric and of N 2 postmetallization anneal (PMA) after gate metallization on the Al 2 O 3 /GaN interface quality is investigated. The interface is characterized by multifrequency capacitance–voltage measurements which show a smaller frequency dispersion after the employment of SPC and PMA treatments with a reduction of the interface trap density D it to a value in the order of 2 × 10 12 cm −2 eV −1 near the conduction band edge. The effectiveness of SPC and PMA is demonstrated in Al 2 O 3 /AlGaN/GaN MIS‐HEMTs by pulsed current–voltage measurements which reveal improved V th stability.