Effects of surface nature of different semiconductor substrates on the plasma enhanced atomic layer deposition growth of Al2O3 gate dielectric thin films. Issue 7 (5th June 2015)

• Record Type: Journal Article
• Authors: Schilirò, Emanuela; Greco, Giuseppe; Fiorenza, Patrick; Tudisco, Cristina; Condorelli, Guglielmo Guido; Di Franco, Salvatore; Roccaforte, Fabrizio; Lo Nigro, Raffaella; Hoffmann, Patrik; Knez, Mato; Vahlas, Constantin; Alexandrov, Sergei
• Is Part Of: Physica status solidi. Volume 12:Issue 7(2015:Jul.)
• Page Start: 980
• Page End: 984
• Publication Date: 2015-06-05
• Subjects: Solid state physics -- Congresses; Solid state physics -- Periodicals; Solid state physics; Conference proceedings; Periodicals; 530.41
• DOI: 10.1002/pssc.201510016
• Languages: English
• ISSNs: 1862-6351

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>In this work, we present a systematic study on the effects of surface nature of two different substrates such as Si(100) and AlGaN/GaN (0001) before atomic layer deposition (ALD) growth of Al<sub>2</sub>O<sub>3</sub> thin films. The Si and AlGaN/GaN surfaces were treated either with: H<sub>2</sub>O<sub>2</sub>:H<sub>2</sub>SO<sub>4</sub> (1:3 piranha solution) for 10 minutes and H<sub>2</sub>O:HF (10:1) for 5 minutes. After surface pretreatment, Al<sub>2</sub>O<sub>3</sub> was immediately deposited at 250 °C by Plasma Enhanced ALD from trimethylaluminum precursor. The film thicknesses were measured to be 28 nm using transmission electron microscopy and different structural evolution has been observed under electron beam analysis, rearraging from amorphous as‐deposited films to epitaxial films depending on the substrate type. Surface morphology obtained by atomic force microscopy in tapping mode shows scattered three‐dimensional nucleation of Al<sub>2</sub>O<sub>3</sub> thin films on Si(001) substrate, while deposition on AlGaN/GaN(0001) resulted in smooth Al<sub>2</sub>O<sub>3</sub> layers. Moreover, X‐ray photoelectron spectroscopy investigation demonstrated a different interfacial interaction between the Al<sub>2</sub>O<sub>3</sub> films and the two different substrates. However, analogous dielectric properties have been evaluated for both films deposited on the two Si(100) and AlGaN/GaN (0001) substrates. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)</p> </abstract>