PECVD of Hafnium Based High K Dielectrics for Field Effect Transistors
نویسنده
چکیده
The semiconductor industry’s rapid development has been predicted by Moore’s law which states that the number of transistors on a silicon chip doubles every 18 months. The demand for high performance at a low cost has translated into downscaling of metal oxide semiconductor field effect transistor (MOSFET) devices resulting in shrinking of SiO2 gate oxide layer. At the present sub nanometer thickness conventional SiO2 gates suffer from high leakage current and reduced reliability due to quantum mechanical tunneling of electrons. Hafnium oxide and hafnium silicate are promising materials to replace SiO2 because they combine high dielectric properties with thermal stability suitable for MOSFET processing temperatures. Hafnium oxide and hafnium silicate films were plasma-enhanced chemical vapor deposited (PECVD) on n-type silicon substrate using oxygen precursors, silane and hafnium tert-butoxide. The films were deposited at 275oC, 360oC, and 425oC substrate temperatures and compared using different oxygen precursors: water vapor, high purity O2 and N2O in order to study their effect on film properties. The deposited films were furnace annealed in air at 1100oC for 30 mins to study their stability at high temperature. The films were characterized for surface chemical composition and states using XPS, and thickness was measured using ellipsometry.
منابع مشابه
16 Hafnium - based High - k Gate Dielectrics
Scaling of silicon dioxide dielectrics has once been viewed as an effective approach to enhance transistor performance in complementary metal-oxide semiconductor (C-MOS) technologies as predicted by Moore’s law [1]. Thus, in the past few decades, reduction in the thickness of silicon dioxide gate dielectrics has enabled increased numbers of transistors per chip with enhanced circuit functionali...
متن کاملHigh - κ dielectrics for advanced carbon - nanotube transistors and logic gates
H igh-κdielectrics have been actively pursued to replace SiO 2 as gate insulators for silicon devices 1. The relatively low κ of SiO 2 (at 3.9) limits its use in transistors as gate lengths scale down to tens of nanometres. High-κ gate insulators afford high capacitance without relying on ultra-small film thickness, thus allowing for efficient charge injection into transistor channels and meanw...
متن کامل45nm Transistor Reliability
It has been clear for a number of years that increasing transistor gate leakage with device scaling would ultimately necessitate an alternative to traditional SiON dielectrics with polysilicon gates. Material systems providing higher dielectric constants, and therefore allowing physically thicker dielectrics, have been the object of extensive research. Such high-k dielectrics, when combined wit...
متن کاملStudy of the Characteristics of Organic Thin Film Transistors with Plasma-Polymer Gate Dielectrics
The effects of gate dielectrics material in organic thin film transistors (OTFTs) were investigated. The gate dielectrics were deposited by plasma enhanced chemical vapor deposition (PECVD) with cyclohexane and tetraethylorthosilane (TEOS) respectively used as organic and inorganic precursors. The gate dielectrics (gate insulators) were deposited as either organic plasma-polymer or organic–inor...
متن کامل