Silk Polymer Coating with Low Dielectric Constant and High Thermal Stability for Ulsi Interlayer Dielectric

1997 ◽  
Vol 476 ◽  
Author(s):  
P. H. Townsend ◽  
S. J. Martin ◽  
J. Godschalx ◽  
D. R. Romer ◽  
D. W. Smith ◽  
...  

AbstractA novel polymer has been developed for use as a thin film dielectric in the interconnect structure of high density integrated circuits. The coating is applied to the substrate as an oligomeric solution, SiLK*, using conventional spin coating equipment and produces highly uniform films after curing at 400 °C to 450 °C. The oligomeric solution, with a viscosity of ca. 30 cPs, is readily handled on standard thin film coating equipment. Polymerization does not require a catalyst. There is no water evolved during the polymerization. The resulting polymer network is an aromatic hydrocarbon with an isotropie structure and contains no fluorine.The properties of the cured films are designed to permit integration with current ILD processes. In particular, the rate of weight-loss during isothermal exposures at 450 °C is ca. 0.7 wt.%/hour. The dielectric constant of cured SiLK has been measured at 2.65. The refractive index in both the in-plane and out-of-plane directions is 1.63. The flow characteristics of SiLK lead to broad topographic planarization and permit the filling of gaps at least as narrow as 0.1 μm. The glass transition temperature for the fully cured film is greater than 490 °C. The coefficient of thermal expansivity is 66 ppm/°C below the glass transition temperature. The stress in fully cured films on Si wafers is ca. 60 MPa at room temperature. The fracture toughness measured on thin films is 0.62 MPa m ½. Thin coatings absorb less than 0.25 wt.% water when exposed to 80% relative humidity at room temperature.

1989 ◽  
Vol 68 (9) ◽  
pp. 1313-1315 ◽  
Author(s):  
C.W. Fairhurst ◽  
D.T. Hashinger ◽  
S.W. Twiggs

Porcelain-fused-to-metal restorations are fired several hundred degrees above the glass-transition temperature and cooled rapidly through the glass-transition temperature range. Thermal expansion data from room temperature to above the glass-transition temperature range are important for the thermal expansion of the porcelain to be matched to the alloy. The effect of heating rate during measurement of thermal expansion was determined for NBS SRM 710 glass and four commercial opaque and body porcelain products. Thermal expansion data were obtained at heating rates of from 3 to 30°C/min after the porcelain was cooled at the same rate. By use of the Moynihan equation (where Tg systematically increases in temperature with an increase in cooling/heating rate), the glass-transition temperatures (Tg) derived from these data were shown to be related to the heating rate.


2016 ◽  
Vol 29 (2) ◽  
pp. 141-150 ◽  
Author(s):  
K Ilango ◽  
P Prabunathan ◽  
E Satheeshkumar ◽  
P Manohar

In this present work, porous mullites (PM0–5) were synthesized through a template-assisted method using various weight percentages of pluronic (P-123). PM5 obtained using 10 wt% of P-123 was found to show maximum porosity (3.8 Å) and low dielectric constant value (2.4). PM5 was functionalized using glycidyl-terminated silane and denoted as FPM and various weight percentages of FPM were reinforced with polybenzoxazine (PBZ) matrix in order to develop FPM/PBZ nanocomposites. The thermal studies indicate that 1.5 wt% of FPM/PBZ nanocomposite showed improved thermal stability with 34% char yield at 800°C and 162°C as glass transition temperature. It also exhibits low dielectric constant (2.6) than that of the neat PBZ matrix and other FPM/PBZ nanocomposites. The microscopic analysis confirms the homogenous dispersion of FPM into the PBZ polymer that has a porous morphology. The results suggest that the as-synthesized mesoporous mullite with low dielectric constant ( k), synthesized via template-assisted method can be used as a reinforcement to decrease the dielectric constant of polymeric material, which is of industrial significance.


RSC Advances ◽  
2016 ◽  
Vol 6 (25) ◽  
pp. 21271-21276 ◽  
Author(s):  
Yung-Chi Chu ◽  
Ming-Hsiao Weng ◽  
Wen-Yi Lin ◽  
Hsin-Jung Tsai ◽  
Wen-Kuang Hsu

Composites made from fibers and epoxy display a low viscous drag and are rarely used as mechanical dampers at room temperature.


1997 ◽  
Vol 476 ◽  
Author(s):  
N. R. Grove ◽  
P. A. Kohl ◽  
S. A. Bidstrup-Allen ◽  
R. A. Shick ◽  
B. L. Goodall ◽  
...  

AbstractWithin the microelectronics industry, there is an ongoing trend toward miniaturization coupled with higher performance. The scaling of transitors toward smaller dimensions, higher speeds, and lower power has resulted in an urgent need for low dielectric constant interlevel insulators. Low dielectric constant interlevel dielectrics have already been identified as being critical to the realization of high performance integrated circuits in the SLA Roadmap. Thus, there exists a need in the microelectronics industry for a thermally stable, noncorrosive low dielectric constant polymer with good solvent resistance, high glass transition temperature, good mechanical performance and good adhesive properties, particularly to copper. In addition, the desired dielectric material should be capable of being processed in environmentally friendly solvents, and the final thermal and electrical performance should not be affected by manufacturing or post environmental conditions. High glass transition temperature polynorbornenes are being developed which provide many of these desired features. This polymer family is produced via a new transition metal catalyzed polymerization. Attributes which make polynorbornene particularly attractive in microelectronics include: (i) excellent thermal performance, (ii) adhesion to conductors without the use of adhesion promoters or barrier layers, (iii) very low moisture absorption (< 0.1 wt %), and (iv) low dielectric constant (2.2 – 2.6). Side groups which have been added to the polynorbornene backbone improve adhesion, dielectric properties and mechanical properties.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 874D-874
Author(s):  
L.E. Towill

Cryopreservation using vitrification has been reported for several plant species. Shoot tips and vitrification solution were placed in semen straws and immersed in liquid nitrogen (LN). Cracking of the external glass occurred, but may be avoided by annealing slightly below the glass transition temperature before immersion. A varying percentage still cracked with some vitrification solutions. Rapid warming also can cause cracking. There is concern that cracking may reduce viability. Shoot tips from Mentha species were used to examine this problem. Glass cracking during either cooling or warming did not produce visible damage to shoot tips. Viability of shoot tips from tubes that cracked during cooling was not different from those that did not crack; however, shoot formation was slightly reduced. Cracking upon warming did not reduce viability nor shoot formation. Very slow warming reduced viability, but warming in either water or air (room temperature) gave higher levels of survival.


Author(s):  
Rafaela Polessi Saturno ◽  
Miriam Dupas Hubinger ◽  
Gabriela Vollet Marson

The brewer's spent yeast hydrolyzed precipitate was used as wall material for microencapsulation of ascorbic acid by the spray drying technique. The wall material had its centesimal composition determined as well as some physicochemical aspects: surface charge, surface tension and glass transition temperature, in order to study the behavior of the material after being atomized and to identify the most suitable core material. Operational conditions were also studied in the spray dryer. After microencapsulation, a 64% yield and a microencapsulation efficiency of 100% were achieved. Microparticle analyses showed low values of water activity and high glass transition temperature, indicating absence of microbiological activity and great particle stability at room temperature, respectively, suggesting that this wall material is suitable for protecting the ascorbic acid.


2017 ◽  
Vol 19 (40) ◽  
pp. 27442-27451 ◽  
Author(s):  
Yao Fu ◽  
Vera Bocharova ◽  
Mengze Ma ◽  
Alexei P. Sokolov ◽  
Bobby G. Sumpter ◽  
...  

Backbone rigidity, counterion size and the static dielectric constant affect the glass transition temperature, segmental relaxation time and decoupling between counterion and segmental dynamics in significant manners.


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