Reliability and hot-electron effects in analog and mixed-mode circuits

• Main Author: Ge, David Ying
• Other Authors: Forbes, Leonard
• Language: en_US
• Published: 2013
• Subjects: Hot carriers; Integrated circuits > Reliability; Metal oxide semiconductor field-effect transistors; Differential amplifiers
• Online Access: http://hdl.handle.net/1957/36252

Reliability of sub-micron analog circuits is directly related to impact ionization and the subsequent changes in threshold voltage and drain current of n-MOSFET devices. This thesis presents theory of the hot-electron effects on the device characteristics and circuit performance, explores several approaches to improve performance at both the device and circuit level, and finally shows a new composite n-MOSFET device which significantly suppresses substrate current - an indication of hot-electron degradation. By using the composite device in the output gain stage of a CMOS differential amplifier with 1p.m technology, the normalized substrate current of the n-channel device is reduced by eight orders of magnitude for a sloping input waveform. The reduction in device substrate current is achieved at the cost of increased area and reduced frequency response. Replacing conventional n-channel devices with composite n-MOSFETs provides a simple way to improve device and circuit reliability without modification of the device structure and/or fabrication process. === Graduation date: 1993