Title :
Accurate Extraction of Effective Channel Length and Source/Drain Series Resistance in Ultrashort-Channel MOSFETs by Iteration Method
Author :
Kim, Junsoo ; Lee, Jaehong ; Song, Ickhyun ; Yun, Yeonam ; Lee, Jong Duk ; Park, Byung-Gook ; Shin, Hyungcheol
Author_Institution :
Seoul Nat. Univ., Seoul
Abstract :
This paper presents a new extraction method for effective channel length (L eff) and source/drain series resistance (R SD) in ultrashort-channel MOSFETs using an iterative process, which is a modified channel resistance method (CRM). Although conventional methods for extracting L eff and R SD, such as the channel resistance and shift-and-ratio methods, are considered to be the most consistent techniques, they are not valid for shorter channel transistors, such as the total resistance (R tot = V DS/I DS) of MOSFETs, and do not scale proportionately with poly-gate length (L poly). This error results from the fact that these methods assume the effective mobility f(mueff) of long- and short-channel transistors to be the same. This assumption inevitably lowers the accuracy of the extracted channel length in ultrashort-channel MOSFETs. Therefore, an improved CRM using an iterative procedure has been proposed. This iteration method takes into account the fact that mobility is degraded in shorter channel devices. By compensating for the mobility in long-channel devices, more accurate approximations for L eff and R SD are extracted compared to conventional methods.
Keywords :
MOSFET; iterative methods; channel length extraction; channel resistance; channel resistance method; channel transistors; iteration method; shift-and-ratio methods; short-channel transistors; source-drain series resistance; ultrashort-channel MOSFET; Capacitance; Circuits; Degradation; Delay; Design engineering; Energy consumption; History; Iterative methods; MOSFETs; Power engineering and energy; Channel resistance method (CRM); MOSFETs; effective channel length; gate–channel capacitance; mobility; source/drain series resistance;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2008.2003081