Thickness monitoring of sub-nanometer scale La_2O_3 films using total X-ray reflection fluorescence spectrometry

摘要

Due to the recent acceleration on device shrinkage in the semiconductor industry, gate oxidernmaterials like silicon dioxide are being substituted by high-k dielectrics. Unfortunately, the poly-siliconrngate and high-k dielectrics react, leading eventually to pinning effects. Consequently, there isrna great demand to use metal oxides such as La_2O_3 in order to prevent these effects. It is very importantrnthat the thickness is ultra-thin and constantly controlled. In this regard, this paper introducesrna method to measure the thickness of sub-nanometer scale La_2O_3 films using Total X-Ray ReflectionrnFluorescence Spectrometry (TXRF). The results confirm the applicability of monitoring thernthickness of sub-nanometer scale La_2O_3 films in the deposition process by TXRF.