Probing defects at interfaces and interlayers of low-dimensional Si/insulator (HfO2; LaAlO3) structures by electron spin resonance
✍ Scribed by A. Stesmans; V.V. Afanas’ev
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 190 KB
- Volume
- 401-402
- Category
- Article
- ISSN
- 0921-4526
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✦ Synopsis
Electron spin resonance (ESR) spectroscopy enables to assess on atomic scale the nature and structural aspects of interfaces and interlayers in semiconductor/insulator hetero structures. This has been applied to (1 0 0)/insulator entities with nm-thin amorphous layers of HfO 2 and LaAlO 3 of high dielectric constant (412) grown on clean (1 0 0)Si by atomic layer chemical vapor deposition and molecular beam deposition, respectively. Through analysis and monitoring of the occurring embedded paramagnetic point defects, including P b -type defects, E 0 , and EX, as a function of VUV irradiation and post-deposition heat treatment, basic information as to the nature, quality, and thermal stability of the interface and interfacial regions has been attained. On the basis of the analysis of P b -type defects (P b0 , P b1 ), archetypal for the Si/SiO 2 interface, the (1 0 0)Si/LaAlO 3 stack is found to be truly abrupt, i.e., no evidence for an Si/SiO 2(x) -type transition in contrast with the Si/HfO 2 entity, where the interface is found to be Si/SiO 2(x) type in the as-grown state. Analysis as a function of post-deposition heating indicates the Si/LaAlO 3 interface to remain stable and abrupt up to T an $800 1C, above which an Si/SiO 2 -type interface develops, while that in Si/HfO 2 evolves to one of closely standard Si/SiO 2 quality, with an SiO 2 interlayer of good quality. The differences in behavior of the studied Si/insulator stacks are discussed in a comparative analysis.