High-k gate stacks on low bandgap tensile strained Ge and GeSn alloys for field-effect transistors

We present the epitaxial growth of Ge and Ge_(0.94)Sn_(0.06) layers with 1.4% and 0.4% tensile strain, respectively, by reduced pressure chemical vapor deposition on relaxed GeSn buffers and the formation of high-k/metal gate stacks thereon. Annealing experiments reveal that process temperatures are...

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Detalhes bibliográficos
Autor: San Andrés Serrano, Enrique
Formato: artículo
Fecha de publicación:2015
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/34692
Acesso em linha:https://hdl.handle.net/20.500.14352/34692
Access Level:acceso abierto
Palavra-chave:537
Interface-trap density
Numerical-simulation
Germanium
Ge_(1-x)Sn_(x).
Electricidad
Electrónica (Física)
2202.03 Electricidad
Descrição
Resumo:We present the epitaxial growth of Ge and Ge_(0.94)Sn_(0.06) layers with 1.4% and 0.4% tensile strain, respectively, by reduced pressure chemical vapor deposition on relaxed GeSn buffers and the formation of high-k/metal gate stacks thereon. Annealing experiments reveal that process temperatures are limited to 350°C to avoid Sn diffusion. Particular emphasis is placed on the electrical characterization of various high-k dielectrics, as 5nm Al_(2)O_(3), 5nm HfO_(2) or 1nm Al_(2)O_(3)/4nm HfO_(2), on strained Ge and strained Ge_(0.94)Sn_(0.06). Experimental capacitance-voltage characteristics are presented and the effect of the small bandgap, like strong response of minority carriers at applied field, are discussed via simulations.