Autor(es)

Chiappim, William ; Watanabe, Marcos ; Dias, Vanessa ; Testoni, Giorgio ; Rangel, Ricardo ; Fraga, Mariana ; Maciel, Homero ; dos Santos Filho, Sebastiao ; Pessoa, Rodrigo

• Tipo de documento: Artigo Científico
• Fonte: NANOMATERIALS; v. 10, n. 2, p. 22-pg., 2020-02-01.

Resumo

In this paper, we report the plasma-enhanced atomic layer deposition (PEALD) of TiO2 and TiO2/Al2O3 nanolaminate films on p-Si(100) to fabricate metal-oxide-semiconductor (MOS) capacitors. In the PEALD process, we used titanium tetraisopropoxide (TTIP) as a titanium precursor, trimethyl aluminum (TMA) as an aluminum precursor and O-2 plasma as an oxidant, keeping the process temperature at 250 degrees C. The effects of PEALD process parameters, such as RF power, substrate exposure mode (direct or remote plasma exposure) and Al2O3 partial-monolayer insertion (generating a nanolaminate structure) on the physical and chemical properties of the TiO2 films were investigated by Rutherford backscattering spectroscopy (RBS), Raman spectroscopy, grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM) techniques. The MOS capacitor structures were fabricated by evaporation of Al gates through mechanical mask on PEALD TiO2 thin film, followed by evaporation of an Al layer on the back side of the Si substrate. The capacitors were characterized by current density-voltage (J-V), capacitance-voltage (C-V) and conductance-voltage (G-V) measurements. Our results indicate that RF power and exposure mode promoted significant modifications on the characteristics of the PEALD TiO2 films, while the insertion of Al2O3 partial monolayers allows the synthesis of TiO2/Al2O3 nanolaminate with well-spaced crystalline TiO2 grains in an amorphous structure. The electrical characterization of the MOS structures evidenced a significant leakage current in the accumulation region in the PEALD TiO2 films, which could be reduced by the addition of partial-monolayers of Al2O3 in the bulk of TiO2 films or by reducing RF power. (AU)

• Processo FAPESP: 11/50773-0 - Núcleo de excelência em física e aplicações de plasmas
• Beneficiário: Ricardo Magnus Osório Galvão
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/10876-6 - Interação plasma-biofilme fúngico: diagnóstico do plasma e do processo de inativação de cepas do gênero Candida spp
• Beneficiário: Anelise Cristina Osorio Cesar Doria
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/05956-0 - 15th International Conference on Atomic Layer Deposition
• Beneficiário: Rodrigo Savio Pessoa
• Modalidade de apoio: Auxílio à Pesquisa - Reunião - Exterior
• Processo FAPESP: 16/17826-7 - Fabricação de células solares MOS utilizando estruturas Al/TiO2/SiO2/Si
• Beneficiário: William Chiappim Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/01265-1 - Síntese e análise microbiológica de substratos poliméricos recobertos com filmes ultra-finos de TiO2 e/ou Al2O3 pela tecnologia de deposição por camada atômica
• Beneficiário: Rodrigo Savio Pessoa
• Modalidade de apoio: Auxílio à Pesquisa - Regular