Pre-passivation Plasma Surface Treatment Effects on Critical Device Electrical Parameters of AlGaN/GaN HEMTs

摘要

This work reports on our investigation of fundamental aspects of surface modification and passivation relating to manufacturability of reliable AlGaN/GaN HEMT devices. We have found that successful mitigation of the RF dispersion in these HEMTs is highly dependent on the type of pre-passivation surface treatment. Surface plasma treatments consisting of C{sub}2F{sub}6, O{sub}2, Cl{sub}2, or NH{sub}3 used in conjunction with PECVD SiN{sub}x allow for the best pulsed I-V characteristics. Less dependent on pre-passivation surface treatment are dc I-V parameters such as interdevice isolation current and gate leakage current, whose magnitude can be altered greatly by varying SiN{sub}x film deposition conditions.