SiO 2 -based xerogels are highly porous materials that may enhance the performance of microelectronic devices due to their extremely low dielectric constants (ε=1.36–2.2). Conventional xerogel and aerogel manufacturing techniques include an expensive and hazardous supercritical drying step to deposit crack free, high porosity films. Ambient drying techniques have recently been developed and in this article, we discuss how the process parameters in the ambient drying process affect the properties of a spin-coated film. Successful spin-on deposition of highly porous (>70%), thick (>1 μm), crack-free, xerogel films was accomplished using a solvent saturated atmosphere during spinning and aging. The saturated atmosphere allowed for the isolation of each processing step and a better understanding of the effects of process variable changes. The film porosity was controlled by varying the extent of silylation (surface modification), the aging time, or the initial water/silane ratio. Fourier transform infrared spectra demonstrated that silylation of xerogel films helps eliminate bound moisture in these films and renders them hydrophobic. Finally, the dielectric constants extrapolated from refractive index measurements were in good agreement with those obtained from our conventional electrical measurements.

Electrical Integrity of State-of-the-Art 0.13 prn SO1 CMOS Devices a n d Circuits T r a n s f e r r e d f o r Three-Dimensional (3D) I n t e g r a t e d C i r c u i t (IC) Fabrication AbstractWe introduce a new scheme for building threedimensional (3D) integrated circuits (ICs) based on the layer transfer of completed devices. We demonstrate for the fmt time that the processes required for stacking active device layers preserve the intrinsic electrical characteristics of stateof-the-art short-channel MOSFETs and ring oscillator circuits, which is critical to the success of high performance 3D ICs.

The experimental results showed that our proposed method can detect the cardiac planes quickly and accurately. Our method is therefore beneficial to both patients and operators.

Spin-on xerogels, which are promising candidates for use as interlayer dielectric materials in future microelectronic devices, change from a Newtonian liquid to a solid gel during processing. Since the rheology of the sol may affect the uniformity of the xerogel films produced, here we relate the rheology of a two-step, acid-base catalyzed, sol-gel system to the thickness and porosity profiles across xerogel films of importance to the microelectronics industry. We also analyze the effect of spin speed on the thickness and porosity of the films. Our rheological studies of the xerogel sol demonstrated that the sol changes from Newtonian far from the gel point, to shear thinning close to the gel point. On films spin coated with shear-thinning sols there is a region of uniformity extending for a distance of about 5 mm from the center. The film thickness and porosity are highest in this region and both quantities decrease towards the edge. If the sol is spun in its Newtonian regime, the resulting films are uniform ͑Ͻ3% thickness and porosity͒. The predictions of film thickness and uniformity based on simple models for spin coating a Newtonian and truncated power law fluid were found to be in good agreement with the experimental observations. The film thickness was varied from 0.485 to 1.9 m by adjusting the spin coating speed from 5900 to 1000 rpm. Over this sixfold range of speed, the porosity was almost constant and varied by less than 10% while the thickness varied by about a factor of 4.

No abstract