Direct Evidence of Polycrystalline Silicon Thin Films Formation during Aluminum Induced Crystallization by In-Situ Heating TEM Observation

The formation behavior of polycrystalline silicon thin films during the aluminum induced crystallization (AIC) process was investigated by scanning transmission electron microscopy (STEM) and in-situ heating transmission electron microscopy (TEM) observations. The STEM observation and electron dispersive X-ray spectroscopy (EDS) analysis of ex-situ heat-treated specimen revealed that the a-Si layer and Al layer switched the positions with each other during the heat treatment, resulting the crystallization of the a-Si layer. Furthermore, the in-situ heating TEM observation and EDS analysis of as-deposited specimen revealed the mixed state of Si and Al in an a-Si/Al film and the lateral growth of crystalline Si grain during the heating. The mechanism of AIC and switching layers were also discussed from the experimental results and the binary phase diagram of Al-Si system

Optimization of Ar-diluted N2 electoron cyclotron resonance plasma for high-quality SiN film growth at low temperature

The growth characteristics and electrical properties of a thin amorphous SiN film formed by Ar-diluted N2 electron cyclotron resonance (ECR) plasma irradiation at a low temperature of 400℃ have been investigated. It is found that SiN film quality is sensitive to the N2 mixing ratio [N2/(N2+Ar)] and a film having a structure nearest to stoichiometric can be obtained with 60% N2 mixing plasma. An optimized substrate bias contributes to suitable plasma etching effect, which leads to the lowest leakage current density of SiN film with a given equivalent oxide thickness(EOT). Two kinds of impurities, N2 molecules and Ar atoms, are found in the as-grown SiN film. The N2 molecules concentration in SiN film has decisive influence on the film quality. An atomically flat interface between Si and SiN film are shown by high-resolution transmission electron microscope micrograph. The as-grown SiN film shows a leakage current more than orders of magnitude lower than that of thermally grown SiO2 having the same EOT

Electrical Properties of TaN/Hf based-high-k Si Gate Stack Structure

We investigated the electrical properties of TaN/HfO2/Si gate stack structure. It was found that the effective work function (Φeff) strongly depends on the interfacial layer formed near the TaN/HfO2 interface. The analysis by X-ray photoelectron spectroscopy (XPS) indicated that Ta oxide is formed near the TaN/HfO2 interface. The results suggested that the modification of Φeff is attributed to the change in the composition of the interfacial layer. The modifiedΦeff is discussed on the basis of the XPS results

TaN/Hf系high-k/Siゲートスタック構造の電気特性

We investigated the electrical properties of TaN/HfO2/Si gate stack structure. It was found that the effective work function (Φeff) strongly depends on the interfacial layer formed near the TaN/HfO2 interface. The analysis by X-ray photoelectron spectroscopy (XPS) indicated that Ta oxide is formed near the TaN/HfO2 interface. The results suggested that the modification of Φeff is attributed to the change in the composition of the interfacial layer. The modifiedΦeff is discussed on the basis of the XPS results