The investigation of aluminum oxide (Al2O3) as gate dielectric in ultra thin body and buried oxide (UTBB) fully depleted (FD) silicon-on-insulator (SOI) transistor

Nowadays, the semiconductor industry requires high performance (speed), low power consumption and high density of transistors on a wafer. This is reached by reducing the dimensions of the metal-oxide-semiconductor field-effect transistor (MOSFET). The rapid shrinking of the transistor feature size includes not only the channel length, but also the gate dielectric thickness. When the current gate dielectric (SiO2) is reduced to 1.3 nm, a number of critical problems appear, such as gate leakage current, band gap change, reliability, boron penetration and so on. To solve these problems, high-k dielectric materials have been considered to replace SiO2 for sub-0.1-um CMOS technology. Among all the high-k dielectric materials, Al2O3 with favorable properties such as low interface trap density, negative fixed charge, high band gap and so on attracts our attention as a potential replacement for SiO2. In this thesis, we fabricate MOS capacitor stacks by using Al2O3-based materials as gate dielectrics. We analyze the advantages and disadvantages of these stacks by C-V measurements and Silvaco-Atlas simulation. For comparison, we prepare several kinds of the reference stacks, with different high-k dielectrics and different thick. Hereafter, all the discussed MOSFETs refer to ultra-thin body and thin buried oxide (UTBB) SOI transistors.