An epitaxial channel MOSFET for improving flicker noise under low supply voltage

Abstract

Introductionsignificantly degraded as supply voltage decreased, while in The application of CMOS to RF telecommunication LSIs has the epitaxial channel and 0.47 pn conventional NMOS cases, come under serious study, because it is expected that low cost the noise characteristics did not degrade under 0.5 -2.0 V. mixed analog and digital LSI will be realized by additional Fig.6 shows dependence of flicker noise on supply voltage for some passive elements to digital CMOS. However required 0.1 1 pm CMOS. In epitaxial channel PMOS case, the noise device performance are different in analog and digital cases. was improved under lower supply voltage while that in the In digital device, supply voltage has decreased in order to NMOS were almost same. The noise of epitaxial channel realize low power consumption as gate length has reduced. MOSFET even at long gate length was beyond 5dBA lower However, analog performance under low supply voltage has than that of conventional case because of better gate oxide not been analyzed in detail.

Low frequency drain current flicker noise model for pocket implanted nano scale n-MOSFET

“…Already few papers have been published focusing on the degradation of drain current flicker noise due to pocket implantation in MOSFETs [9][10][11][12][13][14][15]. New pocket structures, such as, single pocket, asymmetric channel structure, [9,11] and epitaxial channel MOSFETs [12,13], were proposed to reduce the drain current flicker noise by elimination of pocket implantation. The low frequency noise in pocket implanted MOSFETs may result from additional oxide trap creation due to pocket implantation [13], but this was also not supported by the experiment [14].…”

“…New pocket structures, such as, single pocket, asymmetric channel structure, [9,11] and epitaxial channel MOSFETs [12,13], were proposed to reduce the drain current flicker noise by elimination of pocket implantation. The low frequency noise in pocket implanted MOSFETs may result from additional oxide trap creation due to pocket implantation [13], but this was also not supported by the experiment [14]. In [14], it was shown that the non-uniform distribution of threshold voltage along the channel resulting from the pocket implantation is responsible for the low frequency drain current flicker noise degradation, but there step doping profiles are used in the pocket implanted region to model the drain current flicker noise.…”