A study on permitivity of ocides gate dielectric of mosefet

Abstract

The technological and commercial success of the CMOS industry can be directly newlineattributed to the properties of silicon and its oxide, and to scaling. The rate of scaling viz. doubling of the number of transistors integrated per unit area every 18 months was an observation of Gordon Moore, and his prediction of the continuation of the trend has more of less stayed valid till now. However, the technological hurdles faced by the industry now are of an altogether different nature, now that the atomic limit is in sight. Apart from the short channel effects, the major issue is of scaling of the gate diclectric thickness. In order to stave off short channel effects and achieve the kind of transconductance as is required to maintain or improve device performance, the gate capacitance has to be increased, which can be done by scaling the dielectric thickness. This leads to the problems of increased leakage (which is an exponential function of thickness), as well as other reliability problems. Recent years have seen of drastic transformations in the field of metal oxide newlinesemiconductors. Beginning from using oxy- nitride in 2001 as a gate oxide to SiO in 2007, gate oxides has been a topic of constant research. However the present focus is to reduce the leakage nt which is amplified due to constant scaling of the device. Reduction of the newlineleakage current can be done by replacing SiO with a physically thicker layer of metal oxides with a higher relative permittivity (K) such as HfO2, Al2O, and La,0g3.