Metal-insulator-semiconductor capacitors with water-containing hexagonal mesoporous silica (MCM-41) dielectric and high values of capacitance per unit area

Abstract

There are many studies on the synthesis and structure of mesoporous silica, but few reports on mesoporous silica-based electronic devices using planar technology. Fabrication of low-k insulator films from mesoporous silica has been investigated for years. Trapped water is a nuisance for those intending to use mesoporous silica films as low-k materials, but may be beneficial for other applications. In this work, we fabricated Si metal-insulator-semiconductor capacitors (MIS) with a hexagonal mesoporous silica (MCM-41) film as the dielectric and studied their electrical characteristics. We show that water confined within the dielectric is associated with high values of capacitance per unit area (approximately 1 μF cm −2 at 100 Hz) and frequency dispersion of the accumulation capacitance. These devices hold potential for the development of high value MIS capacitors, sensors and biosensors.

Controlling Size Distribution of Silver Nanoparticles using Natural Reducing Agents in MCM‐41@Ag

“…On the contrary, thanks to the spin-coating method, a homogeneous MCM-41 layer with a less rough interface can be obtained, as shown in. [61] The density states are related to the oxidation process of the material in the pores of the MCM-41, as reported by M. Wysocka-Zolopa et al [62] Our results show that the pore diameter of MCM-41@Ag nanocomposite has decreased, as shown in Figure 2. This confirms that the AgNPs are embedded in the pores of MCM-41.…”

“…In this case, we used a chemical method where we first deposited a surfactant film after the silica source was evaporated on the surfactant surface film to grow MCM-41 film, but some parameters such as the solvent, temperature, rate, and time of the evaporation affected the silica surface of the film, obtaining an inhomogeneous surface. [60] Figure 12 shows a cross-sectional SEM of MCM-41 similar to the ones reported in, [61] which offers an inhomogeneous deposited MCM-41 layer and a highly rough interface with the silicon layer, whereas the MCM-41@Ag film used the spin-coating method. On the contrary, thanks to the spin-coating method, a homogeneous MCM-41 layer with a less rough interface can be obtained, as shown in.…”

Solution-processed ultra-low-k thin films comprising single-walled aluminosilicate nanotubes

“…3 Specifically, low-k thin films require a Young's modulus greater than 6 GPa for micro/nanoelectronics; 12,13 however, most existing polymeric thin films have a Young's modulus of only 1 GPa. 7 Low-k thin films made of nanoporous materials, such as zeolites, [14][15][16][17] metal-organic frameworks (MOFs), [18][19][20][21] and mesoporous silica, [22][23][24][25] have higher elastic modulus than polymeric thin films. The Young's modulus values of nanoporous low-k thin films are in the range of 5-20 GPa.…”

Ultrasensitive multiwall carbon nanotube-mesoporous MCM-41 hybrid-based platform for the electrochemical detection of ascorbic acid

“…A decrease in the peak current ( i p = 15 μA) and an important increase in the oxidation overpotential ( E p = 0.382 V) was observed when the electrode was covered by the mesoporous material as a consequence of the electrical insulation properties of MCM-41. 43 On the contrary, the sharp increase in the oxidation current ( i p = 58 μA) accompanied by a significant decrease in the overvoltage ( E p = 0.018 V) at GCE/MWCNT, clearly evidences that the CNTs immobilized on the GCE surface produce a considerable increase in the active area and present an excellent catalytic ability towards the AA electrooxidation (Fig. 1c).…”

“…1 presents a comparison of the cyclic voltammograms for 1.00 × 10 −3 M AA solution obtained at the following electrodes: bare GCE (a), GCE modified with MCM-41 (b), GCE coated with MWCNTs (c), and GCE modified with MWCNT-MCM-41 hybrid (d). The i-E profile obtained at bare GCE shows the typical irreversible electrooxidation of AA (i p = 22 μA, E p = 0.255 V).A decrease in the peak current (i p = 15 μA) and an important increase in the oxidation overpotential (E p = 0.382 V) was observed when the electrode was covered by the mesoporous material as a consequence of the electrical insulation properties of MCM-41 43. On the contrary, the sharp increase in the oxidation current (i p = 58 μA) accompanied by a significant decrease in the overvoltage (E p = 0.018 V) at GCE/ MWCNT, clearly evidences that the CNTs immobilized on the GCE surface produce a considerable increase in the active area and present an excellent catalytic ability towards the AA electrooxidation (Fig.1c).…”