LCE and PAMDLE Effects From Diamond Layout for MOSFETs at High-Temperature Ranges

Abstract

This article presents, for the first time, a study about of behavior of the intrinsic effects from diamond layout style [longitudinal corner effect (LCE) and PArallel connection of MOSFETs with Different channel Lengths Effect (PAMDLE)] for metal–oxide–semiconductor field-effect transistors (MOSFETs) influenced by wide high-temperature ranges. These effects are capable of boosting the electrical performance of analog MOSFETs in relation to that of the standard MOSFET (rectangular gate shape). First, we have developed an experimental comparative study between MOSFETs implemented with the hexagonal layout style diamond MOSFET (DM) and its rectangular MOSFET (RM) counterpart, regarding that they present the same channel width and gate area, operating in a wide high-temperature range (from 300 to 573 K). These devices were manufactured with the technology of bulk complementary MOS (CMOS) integrated circuits (ICs) of 180 nm. The experimental results have shown that DM has obtained a better electrical performance of analog MOSFETs than the one observed in RM counterpart (for example, gains of 67% for saturation drain current and 90% for the transconductance), regardless of temperatures in which they were exposed. 3-D numerical simulations were used to justify the better electrical performance of DMs due to the LCE and PAMDLE effects, in relation to one of the RM counterparts, by observing the behavior of electrostatic potentials, longitudinal electric fields, and drain current densities of the devices as the temperature increases. Besides, a study about the short-channel effect has shown that DM can suppress this effect more effectively than RM at room temperature due to a smaller reduction in effective channel length of DM.