@PhDThesis{França:2015:FaMeSi,
author = "Fran{\c{c}}a, Enrique Klai de",
title = "Fabrica{\c{c}}{\~a}o de membranas de sil{\'{\i}}cio e estudo
do efeito do nitreto de ni{\'o}bio sobre o fator de qualidade
el{\'e}trico nos transdutores do detector Mario Schenberg",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2015",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2015-11-16",
keywords = "sil{\'{\i}}cio, ni{\'o}bio, cavidades ressonantes,
implanta{\c{c}}{\~a}o i{\^o}nica, fator Q, silicon, niobium,
cavity resonators, ion implantation, Q factors.",
abstract = "Visando aprimorar o sistema de transdu{\c{c}}{\~a}o do Detector
de Ondas Gravitacionais Mario Schenberg, foram fabricadas
membranas de sil{\'{\i}}cio com espessuras de 18, 23 e 29
\$\mu\$m, e regi{\~o}es espessas centrais da ordem de 2,5 e 3
mm de lado. O processo de fabrica{\c{c}}{\~a}o destas membranas
consistiu em etapas de fabrica{\c{c}}{\~a}o como
Oxida{\c{c}}{\~a}o t{\'e}rmica, Litografia {\'o}tica e
Corros{\~a}o qu{\'{\i}}mica em KOH. As membranas foram
caracterizadas pela Divis{\~a}o de Astrof{\'{\i}}sica do INPE
(DAS/INPE) para uso na segunda gera{\c{c}}{\~a}o de transdutores
do Detector de Ondas gravitacionais \emph{Mario Schenberg}. As
dimens{\~o}es levaram, portanto, a raz{\~o}es aspecto/espessura
bastante grandes. Tamb{\'e}m foram fabricadas outras membranas de
sil{\'{\i}}cio para uso numa nova gera{\c{c}}{\~a}o de
transdutores do Detector \emph{Mario Schenberg}. Foram obtidas
membranas com espessuras de 38 e 44 \$\mu\$m com o uso do
reator de corros{\~a}o \emph{Atlas Potassium} adquirido para
este fim. Neste caso, o processo de fabrica{\c{c}}{\~a}o destas
membranas envolveu apenas o processo de Corros{\~a}o
qu{\'{\i}}mica em KOH. Em outra frente, cavidades reentrantes
feitas de ni{\'o}bio 99,9\% do tipo \${''}\$klystron\${''}\$
foram usinadas e testadas criogenicamente para
determina{\c{c}}{\~a}o das frequ{\^e}ncias de resson{\^a}ncias
el{\'e}tricas e dos fatores Q n{\~a}o-carregados (Q\$_{eo}\$)
em fun{\c{c}}{\~a}o do acoplament eletromagn{\'e}tico. As
amostras foram submetidas a um tratamento superficial que envolveu
processos qu{\'{\i}}micos/f{\'{\i}}sicos com {\'a}cidos,
sputtering de arg{\^o}nio e implanta{\c{c}}{\~a}o i{\^o}nica
por imers{\~a}o em plasma (3IP) de nitrog{\^e}nio. Com este
tratamento superficial foram obtidos fatores Q n{\~a}o-carregados
(Q\$_{eo}\$) de 1,14.10\$^{4}\$ e 2,52.10\$^{5}\$ em 4,2 K.
Estes resultados indicaram um aumento significativo no efeito da
supercondutividade nas cavidades ap{\'o}s terem sido fortemente
atacadas pela mistura concentrada de {\'a}cidos e ap{\'o}s
sofrerem implanta{\c{c}}{\~o}es seguidas de nitrog{\^e}nio.
Espera-se obter em trabalhos futuros Qeos superiores a
3,0.10\$^{5}\$ em 4,2 K atrav{\'e}s da utiliza{\c{c}}{\~a}o
de ni{\'o}bio de alta pureza e de um tratamento superficial
adequado. Estas cavidades com alto Qeo j{\'a} se encontram
instaladas e em fase de testes no Detector de Ondas Gravitacionais
Mario Schenberg. ABSTRACT: In order to improve the transduction
system of the \emph{Mario Schenberg} Detector, Silicon membranes
were manufactured with thicknesses of 18, 23, and 29 \$\mu\$m,
and thicker central regions with sides of the order of 2.5 to 3
mm. The manufacturing process for these membranes consisted of
manufacturing steps such as thermal oxidation, optical lithography
and chemical etching with KOH. The membranes were characterized by
the Astrophysics Division of INPE (DAS / INPE) for use in the
second generation of the transducers of the gravitational wave
detector \emph{Mario Schenberg}. The dimensions led, therefore,
to large aspect/thickness ratios. Other Silicon membranes were
also made for use in a new generation of the transducers of the
\emph{Mario Schenberg} detector. Membranes were obtained with
thicknesses of 38 and 44 \$\mu\$m using the \emph{Atlas
Potassium} etching reactor acquired for this purpose. In this
case, the manufacturing process of membranes involved only the
process of chemical etching with KOH. On another front,
\${''}\$Klystron\${''}\$ type reentrant cavities made of
Niobium 99.9\% were machined and tested cryogenically to
determine the electrical resonance frequencies and unloaded
electrical Q factors (Q\$_{eo}\$) as a function of
electromagnetic coupling. The samples were subjected to a surface
treatment involving chemical/physical processes with acids, argon
ion sputtering and nitrogen plasma immersion ion implantation
(3IP). With this surface treatment unloaded Q factors
(Q\$_{eo}\$) of 1.14.10\$^{4}\$ and 2.52.10\$^{5}\$ in 4.2 K
were obtained. These results indicated a significant increase in
the effect of superconductivity after the cavity walls have been
heavily attacked by a concentrated acid mixture and after they
have suffered successive nitrogen deployments. Higher values of
the Q\$_{eo}\$ \${'}\$S\$\approx\$ 3,0.10\$^{5}\$ in 4.2
K, in future work, are expected to be obtained using high purity
Niobium with a suitable surface treatment. These cavities, with
high Q\$_{eo}\$, are already installed and being tested in
Gravitational Wave Detector \emph{Mario Schenberg}.",
committee = "Beloto, Antonio Fernando (presidente/orientador) and Aguiar,
Odylio Denys de (orientador) and Mello, Carina Barros and
Oliveira, Rog{\'e}rio de Moraes and Ribeiro, Kilder Leite and
Kostov, Leide Lili Gon{\c{c}}alves da Silva",
copyholder = "SID/SCD",
englishtitle = "Fabrication of Silicon membranes and study of the effect of
niobium nitride on eletrical quality factor in the transducers of
the Mario Schenberg detector",
language = "pt",
pages = "102",
ibi = "8JMKD3MGP3W34P/3KFLKDH",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3KFLKDH",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}