Suppressing the hot carrier injection degradation rate in total ionizing dose effect hardened nMOSFETs

• Published in: Chinese physics B Vol. 20; no. 11; pp. 346 - 352
• Main Author: 陈建军 陈书明 梁斌 何益百 池雅庆 邓科峰
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.11.2011
• Subjects: Annular; Carrier injection; Carriers; CMOS; CMOS工艺; Core hardenability; Degradation; Gates; Retarding; 剂量效应; 改进设计; 热载流子效应; 热载流子注入; 电离; 硬化; 降解率
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/20/11/114220

Annular gate nMOSFETs are frequently used in spaceborne integrated circuits due to their intrinsic good capability of resisting total ionizing dose （TID） effect. However, their capability of resisting the hot carrier effect （HCE） has also been proven to be very weak. In this paper, the reason why the annular gate nMOSFETs have good TID but bad HCE resistance is discussed in detail, and an improved design to locate the source contacts only along one side of the annular gate is used to weaken the HCE degradation. The good TID and HCE hardened capability of the design are verified by the experiments for I/O and core nMOSFETs in a 0.18 μm bulk CMOS technology. In addition, the shortcoming of this design is also discussed and the TID and the HCE characteristics of the replacers （the annular source nMOSFETs） are also studied to provide a possible alternative for the designers.