Compact diamond MOSFET model accounting for PAMDLE applicable down 150 nm node

Abstract

The performance improvements for integrated circuit applications of silicon-on-insulator (SOI) metal-oxide semiconductor field-effect transistors (MOSFETs) implemented with diamond layout style (hexagonal gate geometry) are quantified, thanks to the longitudinal corner effect and parallel association of MOSFETs with different channel lengths effect contributions. Futhermore, an accurate analytical drain current model for planar diamond SOI MOSFET for micrometre scale effective channel lengths is proposed and validated. The concept is then extended by 3D simulations for the 150 nm node fully-depleted SOI n-channel MOSFETs.Introduction: Nowadays, silicon-on-insulator (SOI) complementary metal-oxide semiconductor (CMOS) technology is broadly used to manufacture commercial mixed integrated circuits (ICs) for low-power lowvoltage purposes, and numerous new devices have been studied to improve the electrical performance of analogue and digital ICs [1,2].Considering planar CMOS, the diamond layout style (Fig. 1a) is an alternative device for use in analogue IC applications, to significantly enhance the metal-oxide semiconductor field-effect transistors' (MOSFETs') electrical performance, only by layout change, without causing any extra burden to the CMOS manufacturing process used [3,4].

An Innovative Ellipsoidal Layout Style to Further Boost the Electrical Performance of MOSFETs

“…This study focuses on and describes the experimental results of devices defined in #1 and #4 on Table I [5][6][7]. Other devices presented similar tendencies.…”

“…Regarding the planar CMOS ICs technology, some innovative layouts styles, based on the drain/source-channel interfaces engineering, were proposed to investigate the impact of the gate geometric shape on the electrical performance of MOSFETs, for instance, the Diamond (DM) [5][6][7], Octo (OM) [8], Fish (FM) [9], Wave (WM) [10], and Overlapping-Circular Gate MOSFETs [11]. The ellipsoidal gate shape is another attempt to try to boost the MOSFETs electrical performance, since the resultant longitudinal electric field (LEF) is always composed of three LEF components along the central channel region (longitudinal corner effect, LCE), contrary to the Diamond (two LEF components) [5] and Octo MOSFETs (three LEF components, not totally inside the central gate region) [8].…”

“…The ellipsoidal gate shape is another attempt to try to boost the MOSFETs electrical performance, since the resultant longitudinal electric field (LEF) is always composed of three LEF components along the central channel region (longitudinal corner effect, LCE), contrary to the Diamond (two LEF components) [5] and Octo MOSFETs (three LEF components, not totally inside the central gate region) [8]. The PArallel connection of MOSFETs with Different channel Lengths Effect (PAMDLE) [5][6][7][8] also takes place in the Ellipsoidal MOSFET (EM) structure. Since EM does not present corners, the geometry can increase the breakdown voltage (BV DS ) and Electrostatic Discharge (ESD) robustness, compared to the Diamond (DM), Octo (OM), and Conventional (CM) MOSFETs.…”

Digital Performance of OCTO Layout Style on SOI MOSFET at High Temperature Environment

“…These new effects are: LCE, PAMDLE, DEPAMBBRE [14][15][16][17][18][19] that are able to boost its electrical performance. Some examples of this approach are the Diamond [14][15][16][17][18][19][20][21][22], Octo [23][24][25][26][27], Ellipsoidal [28] and Fish [29] The Octo layout style for MOSFETs was specially invented in order to further boost the Electrostatic Discharge (ESD) tolerance and increase the breakdown voltage (BVDS) as compared to those one found in the Diamond (hexagonal gate shape) layout style. The same effects found (LCE, PAMDLE and DEPAMBBRE) in the Diamond SOI MOSFET also exist in the OSM structure, in which the LCE in the OSM structure is more pronounced, because in this case, it is possible to find a higher resultant longitudinal electric field (LEF).…”

“…Several references about the Octagonal SOI MOSFET (OSM) describe its better performance in terms of saturation drain current (IDS), transconductance (gm), gm/IDS ratio, voltage gain (AV), unit voltage gain frequency (fT), RON, ILEAK, ION, IOFF and ION/IOFF ratio, as compared to those observed in the rectangular SOI MOSFET (RSM) counterparts, regarding the same gate areas (AG) and bias conditions in room-temperature environments [14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”