DocumentCode :
1451012
Title :
on-State Performance Enhancement and Channel-Direction-Dependent Performance of a Biaxial Compressive Strained  \\hbox {Si}_{0.5}\\hbox {Ge}_{0.5} Quantum-Well pMOSFET Along
Author :
Lee, Se-Hoon ; Nainani, Aneesh ; Oh, Jungwoo ; Jeon, Kanghoon ; Kirsch, Paul D. ; Majhi, Prashant ; Register, Leonard Franklin ; Banerjee, Sanjay K. ; Jammy, Raj
Author_Institution :
Microelectron. Res. Center, Univ. of Texas at Austin, Austin, TX, USA
Volume :
58
Issue :
4
fYear :
2011
fDate :
4/1/2011 12:00:00 AM
Firstpage :
985
Lastpage :
995
Abstract :
pMOSFET performance of high Ge content (~50%) biaxial compressive strained SiGe heterostructure channel pMOSFETs is characterized, and performance between 〈110 〉 and 〈100 〉 channel orientations on a (001) substrate is compared for physical channel lengths down to ~80 nm. Temperature-dependent mobility and velocity are characterized for both channel directions. First, it is shown that high Ge content SiGe-based channels can deliver drive current enhancement over unstrained Si below sub-100-nm channel lengths. Second, it is found that, with a higher Ge content SiGe channel under biaxial compressive strain, there is a difference of drive current between 〈110 〉 and 〈100 〉 channel directions, and the difference increases when temperature is lowered and/or when channel length is scaled down. An external series resistance difference is detected between two channel directions, although it appears to be insufficient to explain all the direction-dependent drive current difference. Channel transport behavior in different channel orientations can be clearly observed with low external source/drain (S/D) series resistance achieved with a millisecond S/D dopant activation anneal process while controlling the thermal budget. Two possibilities have been investigated to understand channel-direction-dependent performance: possible differences in effects of device processing impact between two channel directions and anisotropic transport effects from an anisotropic hole band structure, particularly under biaxial compressive strain in a SiGe channel pseudomorphically grown on a Si substrate.
Keywords :
Ge-Si alloys; MOSFET; quantum well devices; semiconductor materials; S-D dopant activation anneal process; S-D series resistance; Si0.5Ge0.5; anisotropic hole band structure; anisotropic transport effects; biaxial compressive strain; channel direction-dependent performance; channel orientations; channel transport behavior; device processing impact; direction-dependent drive current difference; drive current enhancement; heterostructure channel pMOSFET; low-external source-drain series resistance; on-state performance enhancement; physical channel lengths; quantum-well pMOSFET; temperature-dependent mobility; Logic gates; MOSFET circuits; Performance evaluation; Silicon; Silicon germanium; Strain; Substrates; Biaxial compressive strain; channel orientation; hole mobility/velocity enhancement; silicon germanium (SiGe) heterostructure channel pMOSFET;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2011.2105876
Filename :
5714003
Link To Document :
بازگشت