Nanoporous Silica for Low κ Dielectrics

1997 ◽  
Vol 495 ◽  
Author(s):  
Teresa Ramos ◽  
Steve Wallace ◽  
Douglas M. Smith
Keyword(s):  
Dielectric Constant ◽  
Integrated Circuit ◽  
Dielectric Material ◽  
Fundamental Problem ◽  
Scale Up ◽  
Current Status ◽  
Nanoporous Silica ◽  
Interconnect Delay ◽  
Small Pore ◽  
Deposition Processes

ABSTRACTAs integrated circuit sizes decrease below 0.25 microns, device performance will no longer improve at the same rate as for past generations because of RC interconnect delay which becomes significant as compared to the intrinsic gate delay. The parallel approaches to partially address this fundamental problem are to use a lower resistance metal (i.e., copper instead of aluminum) and to use a dielectric material with a dielectric constant significantly below that of dense silica (∼4). Recently, considerable progress has been made in development of thin films of nanoporous silica (also known as aerogels or low density xerogels) for these ILD and IMD applications. Advantages of these materials include high thermal stability, small pore size, and similarity to conventional spin-on deposition processes, spin-on glass precursors and final material (silica). The dielectric constant of nanoporous silica can be tailored between ∼1 and 3 which allows its’ implementation at multiple technology nodes in integrated circuit manufacture starting with the 0.18 micron node.Research and development efforts at Nanoglass over the last several years have focused on; 1) simpler and more reproducible deposition processes, 2) a more complete understanding of processing-property relationships for this material, 3) scale-up of manufacturing to yield a range of precursor products with stability for at least six months and very high purity, and 4) working with customers to integrate this material into both aluminum/gapfill and copper/damascene process flows. Nanoglass has now developed a new process which considerably reduces the number of process steps and allows independent control of both film thickness and porosity. The current status of process and precursor development and device integration efforts for nanoporous silica is discussed.

Nanoporous Silica For Low K Dielectrics

1998 ◽  
Vol 511 ◽  
Author(s):  
T. Ramos ◽  
K. Rhoderick ◽  
R. Roth ◽  
L. Brungardt ◽  
S. Wallace ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Pore Size ◽  
Integrated Circuit ◽  
Dielectric Material ◽  
Scale Up ◽  
Nanoporous Silica ◽  
Interconnect Delay ◽  
Small Pore ◽  
Deposition Processes ◽  
Technology Nodes

ABSTRACTAs integrated circuit sizes decrease below 0.25 microns, device performance will no longer improve at the same rate as for past generations because of RC interconnect delay which becomes significant as compared to the intrinsic gate delay. Parallel approaches to address this are to use a lower resistance metal (i.e., copper instead of aluminum) and to use a dielectric material with a dielectric constant significantly below that of dense silica (∼4). Recently, considerable progress has been made in development of thin films of nanoporous silica for these applications. Advantages include high thermal stability, small pore size, similarity to conventional spin-on deposition processes and spin-on glass precursors and final material (silica). The dielectric constant of nanoporous silica can be tailored between ∼1 and 3 which allows its’ implementation at multiple technology nodes in integrated circuit manufacture.Recent development efforts have been focused on; 1) simpler and more reproducible deposition processes, 2) a more complete understanding of processing-property relationships for this material, 3) scale-up of manufacturing to yield a range of precursor products with stability for at least six months and very high purity, and 4) working with customers to integrate this material into both aluminum/gapfill and copper/damascene process flows. This paper targets several specific issues related to nanoporous silica use including water adsorption, pore size distribution control, processing at commercially viable throughputs, and obtaining thickness and dielectric uniformity across 200 mm wafers and wafer to wafer.

Characterization of MgZnO Thin Film for 1 GHz MMIC Applications

2013 ◽  
Vol 832 ◽  
pp. 310-315
Author(s):  
R. Ahmad ◽  
M.S. Shamsudin ◽  
M. Salina ◽  
S.M. Sanip ◽  
M. Rusop ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Loss Tangent ◽  
Integrated Circuit ◽  
Annealing Temperature ◽  
Dielectric Material ◽  
Sol Gel ◽  
Size Reduction ◽  
High Frequencies

MgZnO thin films are proposed as a new dielectric material for 1 GHz monolithic microwave integrated circuit (MMIC) applications. The high permittivity of this material enables size reduction; furthermore this can be fabricated using a low cost processing method. In this work, MgZnO/Pt/Si thin films were synthesized using a sol-gel spin coating method. The samples were annealed at various temperatures with the effects on physical and electrical properties investigated at direct current (DC) and high frequencies. The physical properties of MgZnO thin film were analyzed using X-Ray diffraction, with the improvements shown in crystalline structure and grain size with increasing temperature up to 700 °C. DC resistivity of 77 Ωcm at higher annealing temperature obtained using a four point probe station. In order to prove the feasibility at high frequencies, a test structure consisting of a 50 Ω transmission line and capacitors with 50 × 50 μm electrode area were patterned on the films using electron beam lithography. The radio frequency (RF) properties were measured using aWiltron 37269Avector network analyzer andCascade Microtechon-wafer probes measured over a frequency range of 0.5 to 3 GHz. The dielectric constant, loss tangent and return loss, S11improve with the increment annealing temperature. The dielectric constant was found to be 18.8, with loss tangent of 0.02 at 1 GHz. These give a corresponding size reduction of ten times compared to conventional dielectrics, silicon nitride (Si3N4). These indicate that the material is suitable to be implemented as a new dielectric material for 1GHz MMIC applications.

scholarly journals The Evolution of Organosilicon Precursors for Low-k Interlayer Dielectric Fabrication Driven by Integration Challenges

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4827
Author(s):  
Nianmin Hong ◽  
Yinong Zhang ◽  
Quan Sun ◽  
Wenjie Fan ◽  
Menglu Li ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Data Storage ◽  
Integrated Circuit ◽  
Porous Silica ◽  
Dielectric Materials ◽  
Interlayer Dielectric ◽  
Damascene Process ◽  
Key Issues ◽  
Deposition Processes ◽  
Low K

Since the application of silicon materials in electronic devices in the 1950s, microprocessors are continuously getting smaller, faster, smarter, and larger in data storage capacity. One important factor that makes progress possible is decreasing the dielectric constant of the insulating layer within the integrated circuit (IC). Nevertheless, the evolution of interlayer dielectrics (ILDs) is not driven by a single factor. At first, the objective was to reduce the dielectric constant (k). Reduction of the dielectric constant of a material can be accomplished by selecting chemical bonds with low polarizability and introducing porosity. Moving from silicon dioxide, silsesquioxane-based materials, and silica-based materials to porous silica materials, the industry has been able to reduce the ILDs’ dielectric constant from 4.5 to as low as 1.5. However, porous ILDs are mechanically weak, thermally unstable, and poorly compatible with other materials, which gives them the tendency to absorb chemicals, moisture, etc. All these features create many challenges for the integration of IC during the dual-damascene process, with plasma-induced damage (PID) being the most devastating one. Since the discovery of porous materials, the industry has shifted its focus from decreasing ILDs’ dielectric constant to overcoming these integration challenges. More supplementary precursors (such as Si-C-Si structured compounds), deposition processes (such as NH3 plasma treatment), and post porosity plasma protection treatment (P4) were invented to solve integration-related challenges. Herein, we present the evolution of interlayer dielectric materials driven by the following three aspects, classification of dielectric materials, deposition methods, and key issues encountered and solved during the integration phase. We aim to provide a brief overview of the development of low-k dielectric materials over the past few decades.

Nanoporous Silica for Low k Dielectrics

1996 ◽  
Vol 443 ◽  
Author(s):  
Teresa Ramos ◽  
Kevin Roderick ◽  
Alok Maskara ◽  
Douglas M. Smith
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Film Thickness ◽  
Pore Size ◽  
Ambient Pressure ◽  
Porous Solids ◽  
Nanoporous Silica ◽  
Low Density ◽  
Trade Offs ◽  
Small Pore

AbstractConsiderable progress has been made in development of thin films of nanoporous silica (also known as aerogels or low density xerogels) for ILD and IMD applications. Advantages of these materials include high thermal stability, small pore size, and similarity to conventional deposition processes, precursors and final material (silica). We have previously reported success in synthesizing low density, low dielectric constant (K<2) thin films using ambient pressure processing. However, processing of those films was complicated due to large number of process steps and difficulties in independently controlling both film thickness and film porosity.Nanoglass has now developed a new process which considerably reduces the number of process steps and allows independent control of both film thickness and porosity. The dielectric constant of the films can be tailored between 1.3 and 2.5. These films have improved mechanical properties due to controlled pore size and narrow pore size distribution and also because of higher density. The trade-offs between density, mechanical strength and dielectric constant for these types of porous solids will be elucidated. The known properties of the film and the process flow for deposition and post-deposition curing and the role of the relative rates of reaction, gelation, aging, and drying will be presented.

Porous Silica Xerogel Processing And Integration For Ulsi Applications

1998 ◽  
Vol 511 ◽  
Author(s):  
Changming Jin ◽  
Scott List ◽  
Eden Zielinski
Keyword(s):  
Dielectric Constant ◽  
Dielectric Material ◽  
Porous Silica ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Silica Xerogel ◽  
Future Technology ◽  
Small Pore ◽  
High Dielectric

ABSTRACTWith a tunable ultra low dielectric constant, porous silica xerogel is an attractive dielectric material for ULSI interconnect applications and is potentially extendable to multiple future technology nodes. Porous silica xerogel films have been processed and integrated into device test structures as ultra low k intermetal dielectrics. A fully automated thin film deposition process is recently developed and gives high throughput and good repeatability. A surface modification technique is used to make the films hydrophobic. The film dielectric constant is measured to be less than 2, depending on porosity. Because of the small pore sizes, the films display high dielectric break down strength. With proper shrinkage control, porous silica xerogel shows excellent gapfill capabilities. Integration of the porous silica xerogel material into CMP planarized double level metal (DLM) test structures with both Al and W plugs in a gapfill scheme is successful. Porous silica xerogel structures provide 14% and 35% total capacitance reduction compared to structures with hydrogen silsesquioxane (HSQ) and high density plasma (HDP) oxide respectively. Reliability and current leakage data of porous silica xerogel are comparable to that of HSQ. Feasibility of integrating porous silica xerogel into Cu damascene structures is also demonstrated. Cu/xerogel damascene structures exhibit improvements in both resistance and capacitance compared with convention Al/Oxide gapfill structures.

Evaluation of PTFE Nanoemulsion as a Low Dielectric Constant Material ILD

1996 ◽  
Vol 443 ◽  
Author(s):  
S. C. Sun ◽  
Y. C. Chiang ◽  
C. T. Rosenmayer ◽  
J. Teguh ◽  
H. Wu
Keyword(s):  
Dielectric Constant ◽  
Integrated Circuit ◽  
Moisture Absorption ◽  
Dielectric Material ◽  
Dielectric Strength ◽  
Index Of Refraction ◽  
Low Dielectric Constant ◽  
Nanoparticle Dispersion ◽  
Positive Photoresist ◽  
Low Dielectric

AbstractPolytetrafluoroethylene (PTFE) has been studied as a low dielectric constant material for ULSI. A novel nanoparticle dispersion of PTFE was developed that permits the spin-coat deposition of PTFE with a thickness range of 0.2 to 1.5 μm. These PTFE nanoemulsions are aqueous emulsions containing sub-50 nm size PTFE particles and surfactant that are thermodynamically stable, optically clear, and have low viscosity and surface tension. The films cast from this nanoemulsion are uniform in thickness with a standard deviation of < 2%. From FTIR spectra, significant amounts of C-F bonds (1153 cm−1 and 1211 cm−1) are detected in the films. The index of refraction from ellipsometry measurement is about 1.35 and the dielectric constant measured from high frequency C-V curves is about 1.85. The dielectric strength is about 170 V/ μm. TGA data indicates a weight loss rate of less than 0.25%/hr. at 425 °C. The moisture absorption is less than 0.01%. After sintering, the films are extremely resistant to chemical attack by sulfuric acid, buffered HF, and positive photoresist developer. The etch rate in an oxygen plasma at 30 W is around 200 nm/min. Stud pull tests indicate good adhesion to SiO2, Al, and Cu. Results of thermal, dielectric, chemical, and adhesion tests indicate that these PTFE films have potential for use as an integrated circuit dielectric material.

Skin–core structured fluorinated MWCNTs: a nanofiller towards a broadband dielectric material with a high dielectric constant and low dielectric loss

2018 ◽  
Vol 6 (9) ◽  
pp. 2370-2378 ◽  
Author(s):  
Yang Liu ◽  
Cheng Zhang ◽  
Benyuan Huang ◽  
Xu Wang ◽  
Yulong Li ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Epoxy Composite ◽  
Low Dielectric ◽  
High Dielectric

A novel skin–core structured fluorinated MWCNT nanofiller was prepared to fabricate epoxy composite with broadband high dielectric constant and low dielectric loss.

Sol–gel deposited xerogel, aerogel and porogen based porous low-k thin films: A comparative investigation

2021 ◽  
pp. 2140019
Author(s):  
Swati Gupta ◽  
Anil Gaikwad ◽  
Ashok Mahajan ◽  
Lin Hongxiao ◽  
He Zhewei
Keyword(s):  
Dielectric Constant ◽  
Sol Gel ◽  
Comparative Investigation ◽  
Crosstalk Noise ◽  
Nanoelectronic Devices ◽  
Low Dielectric ◽  
Interconnect Delay ◽  
Xerogel Films ◽  
Low K ◽  
Porosity Percentage

Low dielectric constant (Low-[Formula: see text]) films are used as inter layer dielectric (ILD) in nanoelectronic devices to reduce interconnect delay, crosstalk noise and power consumption. Tailoring capability of porous low-[Formula: see text] films attracted more attention. Present work investigates comparative study of xerogel, aerogel and porogen based porous low-[Formula: see text] films. Deposition of SiO2 and incorporation of less polar bonds in film matrix is confirmed using Fourier Transform Infra-Red Spectroscopy (FTIR). Refractive indices (RI) of xerogel, aerogel and porogen based low-[Formula: see text] films observed to be as low as 1.25, 1.19 and 1.14, respectively. Higher porosity percentage of 69.46% is observed for porogen-based films while for shrinked xerogel films, it is lowered to 45.47%. Porous structure of low-[Formula: see text] films has been validated by using Field Emission Scanning Electron Microscopy (FE-SEM). The pore diameters of porogen based annealed samples were in the range of 3.53–25.50 nm. The dielectric constant ([Formula: see text]) obtained from RI for xerogel, aerogel and porogen based films are 2.58, 2.20 and 1.88, respectively.

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