Title :
Effects of boron penetration and resultant limitations in ultra thin pure-oxide and nitrided-oxide gate-films
Author :
Morimoto, T. ; Momose, H.S. ; Ozawa, Y. ; Yamabe, K. ; Iwai, H.
Author_Institution :
Toshiba Corp., Kawasaki, Japan
Abstract :
The boron penetration effect was compared for p/sup +/ poly gate PMOSFETs with pure oxide gates and nitrided oxide gates. For a gate thickness of 6.5 nm, reduced boron dosage and rapid thermal processing solve the problem of boron penetration in the pure oxide case. However, when the film thickness is less than 6.5 nm, only a nitrided oxide film can solve the problem. From the results of EDX analysis in nitrided oxide films, it was found that nitrogen build-up at the interface is small and that a nitrogen concentration of only a few percent leads to complete suppression of boron penetration down to the 2 nm range of film thickness. Excellent characteristics in 2.6 nm nitrided oxide gate p-MOSFETs, free from boron penetration effects, were demonstrated.<>
Keywords :
boron; dielectric thin films; insulated gate field effect transistors; semiconductor-insulator boundaries; 2 to 6.5 nm; 2.6 nm; B penetration effect; EDX analysis; PMOSFETs; Si:B; SiNO; SiO/sub 2/; gate thickness; nitrided-oxide gate-films; p/sup +/ poly gate; pure oxide gates; rapid thermal processing; ultrathin films; Boron; Lead compounds; MOSFET circuits; Nitrogen; Rapid thermal processing;
Conference_Titel :
Electron Devices Meeting, 1990. IEDM '90. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
DOI :
10.1109/IEDM.1990.237140
