Low-Temperature Polycrystalline Silicon Thin Film Transistor Nonvolatile Memory Using Ni Nanocrystals as Charge-Trapping Centers Fabricated by Hydrogen Plasma Process

Abstract

Processes for fabricating a Ni nanocrystal (NC)-assisted low-temperature polycrystalline silicon thin film transistor (LTPS-TFT) nonvolatile memory device of noble stack below 600 degrees C were successfully developed. The NCs were fabricated in H-plasma atmosphere by heating a nanosized Ni film to realize an appropriate nanoparticle distribution. Results show that NCs with a number density of similar to 5 x 10(11) cm(-2) and a particle diameter of 4 to 12 nm can successfully be fabricated as charge-trapping centers for enhancing the device performance. The results also indicate that the data retentions at the initial time and after 10(4) s for a SiO(2)/Ni-NCs/Si(3)N(4)/SiO(2) gate under the present stack of devices are about 2.2 and similar to 1.1 V, respectively. (C) 2010 The Japan Society of Applied Physics