Electrical Characteristics of Mesoporous Pure-Silica–Zeolite Film

Seo, T.; Yoshino, T.; Cho, Yoshinori; Hata, Nobuhiro; Kikkawa, Takamaro

doi:10.1143/jjap.46.5742

Cited by 12 publications

(19 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Etching the highly porous material, postetch-cleans as well as its integration into current metallization scheme are doable, but may not be simple extension of current processes. One material is pure-silica-zeolite 370 which, depending on its porosity, could reach j values below 2.3, but with an increase in leakage current. Alternately, a nonporous low-j dielectric can be used.…”

Section: New Materialsmentioning

confidence: 99%

Plasma etching: Yesterday, today, and tomorrow

Donnelly¹,

Kornblit²

2013

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

676

422

View full text Add to dashboard Cite

The field of plasma etching is reviewed. Plasma etching, a revolutionary extension of the technique of physical sputtering, was introduced to integrated circuit manufacturing as early as the mid 1960s and more widely in the early 1970s, in an effort to reduce liquid waste disposal in manufacturing and achieve selectivities that were difficult to obtain with wet chemistry. Quickly,the ability to anisotropically etch silicon, aluminum, and silicon dioxide in plasmas became the breakthrough that allowed the features in integrated circuits to continue to shrink over the next 40 years. Some of this early history is reviewed, and a discussion of the evolution in plasma reactor design is included. Some basic principles related to plasma etching such as evaporation rates and Langmuir–Hinshelwood adsorption are introduced. Etching mechanisms of selected materials, silicon,silicon dioxide, and low dielectric-constant materials are discussed in detail. A detailed treatment is presented of applications in current silicon integrated circuit fabrication. Finally, some predictions are offered for future needs and advances in plasma etching for silicon and nonsilicon-based devices.

show abstract

Section: New Materialsmentioning

confidence: 99%

Plasma etching: Yesterday, today, and tomorrow

Donnelly¹,

Kornblit²

2013

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

676

422

View full text Add to dashboard Cite

show abstract

“…Butanol and a surfactant were added to the suspension while stirring, so that mesoscopic size pores of several nm in diameter were formed. The molar ratio of the solution was as follows TBAOH: TEOS: (EO) 13 (PO) 20 (EO) 13 ; 1.00:1.98:56.9. Spin coating of zeolite precursor was done at 1500 rpm for 20 s at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Influence of Synthesis Process on Mechanical and Electrical Characteristics of Mesoporous Pure Silica-Zeolite

Seo

Yoshino

Ohnuki

et al. 2011

J. Electrochem. Soc.

View full text Add to dashboard Cite

The dielectric constant, elastic modulus and reliability of the pure silica-zeolite composite film which was formed by self-assembly of porous silica having hydrothermally crystallized zeolite nanoparticles. Fourier-transform-infrared spectroscopy indicated that Si-OH and O-H bonds decreased by zeolite formation, resulting in the decrease of the dielectric constant. Silylation hardening by 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) vapor treatment could decrease the dielectric constant due to the decrease of Si-OH and O-H bonds. The elastic modulus of 7.03 GPa and the dielectric constant of 1.94 were achieved for the meso-porous silica-zeolite film by silylation hardening. Furthermore, mean-time-to-failure (MTF) lifetime of time-dependent dielectric breakdown (TDDB) is longer than ten years at 125 C under the electric field of 3.4 MV=cm.With scaling down of semiconductor device dimensions, a signal delay time has increased due to the increase of interconnect resistance and parasitic capacitance. 1 In order to overcome this problem, low dielectric constant (low-k) interlayer dielectric films are needed. A lower dielectric constant can lead to lower power dissipation and less interline crosstalk as well as lower RC delay. The porous silica which is the composite of silica and pores has been investigated as a possible candidate of ultra low-k films. 2 However, the mechanical strength of the porous silica was degraded because the elastic modulus decreased due to its pore structure. 3 The mechanical properties of the low-k films are of great importance because the films must withstand the stresses developed during the packaging process and chemical mechanical polishing (CMP) in integrated circuits chip fabrication process. Therefore, control of the skeletal silica structure in terms of elastic modulus is important.Recently, nanostructured zeolite films have been studied and demonstrated to be a promising low-k material. The young's modulus of the zeolite is 110 GPa, 4 which is larger than that of SiO 2 (73 GPa). The high porosity of the zeolite films can maintain comparatively higher mechanical strength than amorphous porous silica. Furthermore, it has the better thermal conductivity and hydrophobicity than SiO 2 . 5À10 The mobil eleven (MEL) type zeolite was adopted in this work, whose pore diameters are 0.53 and 0.54 nm in the silica skelton. 11,12 In this paper, effects of zeolite crystal formation processes on the film properties of pure silica zeolite films are investigated. ExperimentalThe pure silica MEL zeolite was prepared by hydrothermal crystallization. The film was formed by a spin on process of zeolite nanoparticle suspension. The preparation of the zeolite films had two steps. One was synthesis of the zeolite nanoparticle suspension and the other was spin coating of the suspension onto Si wafer.The process flow is shown in Fig. 1. A few nm thick native oxide was formed on the surface of Si wafer. Tetrabutylammonium hydroside (TBAOH) was mixed with ethylalcohol (EtOH), tetraethylorthosilicate (TEOS), a...

show abstract

“…The preparation of films by spin coating of nanocrystal suspensions of Silicalite‐1 and ‐2 type zeolites is being intensively investigated for their applicability as ultra‐low‐ k materials in nanoelectronic devices 1–4. Despite their low dielectric constant, they offer limitations related to the use of zeolite nanocrystal suspensions with particle sizes of ∼40–80 nm 1, 3e, 3f.…”

Section: Average Hydrodynamic Particle Diameter Measured By Dls [Nm]mentioning

confidence: 99%

Comment on “MEL‐type Pure‐Silica Zeolite Nanocrystals Prepared by an Evaporation‐Assisted Two‐Stage Synthesis Method as Ultra‐Low‐k Materials”

Eslava

Seo

Kirschhock

et al. 2010

Adv Funct Materials

View full text Add to dashboard Cite

A bottle-neck in the application of zeolite films as low-k dielectrics is the presence of 40-80 nm zeolite nanoparticles composing the film, causing both large mesopores and hampering the grooving of nanofeatures. Evaporation-assisted two-stage synthesis of MELtype zeolite nanosuspensions avoiding 40-80 nm zeolite nanoparticle formation in suspension was recently proposed in this journal for the preparation of zeolite films with improved properties and with possibility to groove nanofeatures at 65 nm. [1] We reproduced such zeolite films using that procedure involving well dispersed zeolite nanosuspension and characterized the porosity using ellipsometric porosimetry. We concluded that the approach of evaporation-assisted two-stage synthesis of MEL-type zeolite nanosuspensions does not lead to films with small and narrow pore size distribution where nanofeatures can be grooved. Pores of up to 50 nm width were observed in final spin-on MEL-zeolite films The preparation of films by spin coating of nanocrystal suspensions of Silicalite-1 and -2 type zeolites is being intensively investigated for their applicability as ultra-low-k materials in nanoelectronic devices. [1][2][3][4] Despite their low dielectric constant, they offer limitations related to the use of zeolite nanocrystal suspensions with particle sizes of 40-80 nm. [1,3e,3f ] The main drawbacks are the important surface roughness, the formation of large mesopores between individual nanocrystals, and the difficulty to groove nanofeatures. Although different zeolite syntheses involve the formation of primary zeolite particles smaller than 20 nm, these tend to agglomerate into larger ones at high concentrations or during the crystallization process. [5] In a recent publication in this journal Yan's group claimed to have overcome the agglomeration drawback by optimizing the synthesis conditions of MEL zeolite suspensions. [1] The authors reported that an evaporation-assisted two-stage synthesis of MELtype zeolite nanosuspensions significantly avoids the agglomeration in suspension of 14 nm MEL primary particles into larger 60-80 nm secondary particles. Briefly, the method consists of evaporating part of the solvent between two hydrothermal treatments of the synthesis mixture of the MEL-type zeolite. By evaporating 60 wt% of solvent, 98.4% of primary particles were reported to not agglomerate and be preserved in the final suspension (so called E-60). This was found in the dynamic light scattering analysis on this MEL suspension diluted with abundant water (0.05 mL E-60 in 4 mL water). The use of MEL suspensions with 98.4% of particles being only 14 nm (i.e., avoiding almost all the agglomeration) should minimize the formation of mesopores between the nanocrystals, and moreover, grooving small features of few tens of nm should be feasible. However, we encountered that the use of such MEL suspensions still leads to films with relatively wide pore size distribution.We synthesized MEL nanocrystal suspensions following carefully the described procedures in ref.[1] ...

show abstract

Electrical Characteristics of Mesoporous Pure-Silica–Zeolite Film

Cited by 12 publications

References 11 publications

Plasma etching: Yesterday, today, and tomorrow

Plasma etching: Yesterday, today, and tomorrow

Influence of Synthesis Process on Mechanical and Electrical Characteristics of Mesoporous Pure Silica-Zeolite

Comment on “MEL‐type Pure‐Silica Zeolite Nanocrystals Prepared by an Evaporation‐Assisted Two‐Stage Synthesis Method as Ultra‐Low‐k Materials”

Contact Info

Product

Resources

About