A methodology for projecting SiO2 thick gate oxide reliability on trench power MOSFETs and its application on MOSFETs VGS rating. (March 2016)

• Record Type: Journal Article
• Authors: Efthymiou, E.; Rutter, P.; Whiteley, P.
• Is Part Of: Microelectronics and reliability. Volume 58(2016)
• Page Start: 26
• Page End: 32
• Publication Date: 2016-03
• Subjects: Trench MOSFETs -- Thick gate oxide -- Reliability -- TDDB -- E-model -- Weibull -- VGS rating; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.11.021
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: In this work, a methodology based on the E-model for the reliability projection of a thick (> 20 nm) SiO2 gate oxide on a vertical trench power MOSFET, is presented. Experimental results suggest that a Logic Level (LL) trench MOSFET with 35 nm of gate oxide can be rated at VGS = + 12 V if one assumes continuous DC Gate-Source bias of VGS = + 12 V at T = 175 °C for 10 years at a defect level of 1 Part Per Million (PPM). We will demonstrate that if we take into account MOSFET device lifetime as dictated by the Automotive Electronics Council (AEC Q101) mission profile, then devices can be rated higher to VGS = + 14.7 V at T = 175 °C for the same PPM level (1 PPM). The application of the methodology for establishing the oxide thickness, tox, for any required voltage rating, is discussed. Highlights: We present reliability results of thick gate oxides on power trench MOSFETs. We derive activation energy & field acceleration parameters from Trench MOSFETs. We comment on VGS rating for continuous & mission profile operation of MOSFET. We examine the effect of gate oxide thickness variation across Wafer on VGS rating. We report VGS rating of 12 V for a Logic level MOSFET for 10 years at Tj(max) = 175 °C.