The first encompassing treatise of this new, but very important field puts the known physical limitations for classic 2D electronics into perspective with the requirements for further electronics developments and market necessities. This two-volume handbook presents 3D solutions to the feature density problem, addressing all important issues, such as wafer processing, die bonding, packaging technology, and thermal aspects.It begins with an introductory part, which defines necessary goals, existing issues and relates 3D integration to the semiconductor roadmap of the industry, before going on to cover processing technology and 3D structure fabrication strategies in detail. This is followed by fields of application and a look at the future of 3D integration.The contributions come from key players in the field, from both academia and industry, including such companies as Lincoln Labs, Fraunhofer, RPI, ASET, IMEC, CEA-LETI, IBM, and Renesas.

Benzocyclobutene resin has been modified to allow fabrication of polymer coated Cu foil. New formulations show improved flexibility, flaking resistance, low tackiness, and better resin flow control during hot pressing, while keeping BCB's inherent advantages such as low moisture pick-up, high heat stability and excellent dielectric properties. BCB coated Cu foil has been laminated on FR-4 board by conventional hot press processing. Relevant build-up board processes such as laser via formation, electroless plating and drill through holes were accomplished. Test boards with a BCB build-up layer per side were evaluated and excellent reliabilities and excellent electrical performance was confirmed.

Polymer coatings are applied to chips and passive components to provide stress relief between the device/component and the plastic package and/or to provide mechanical and environmental protection. The semiconductor industry is actively pursuing a one mask, photosensitive dielectric process for stress-buffer and secondary passivation of memory die. A one mask photo-benzocyclobutene (BCB) process is compared to traditional two mask wet etch processes. This new one mask process reveals 1/3 the total wafer processing time and equivalent reliability (traditional MIL 883C testing) for passivated 100 lead static random access memory components (SRAMs). Reliability data are also presented for GaAs chips, and NiCr and TaN resistors which have been passivated by BCB.

This paper demonstrates how laminate based printed-wiring-board technology (PWB) and thin film deposited dielectric technology (MCM-D) can be combined to form a low-cost solution for microelectronic interconnect schemes which require high density circuitry. A multilayer telecommunications module was fabricated to demonstrate the feasibility of this MCM-LD concept. Standard copper-clad laminates were processed using conventional PWB techniques to form the first level of metal interconnects (75 /spl mu/m lines and spaces). A photosensitive benzocyclobutene layer was coated onto the boards and patterned to form 50 /spl mu/m/spl times/200 /spl mu/m nested vias down to the metal lines. A second metal interconnect layer was formed from a sputtered seed layer and plated up copper. Chip interconnection was carried out using gold wirebonding. Several large-area-processing (LAP) techniques were evaluated to determine the compatibility of the two interconnect technologies and to demonstrate the cost advantages of manufacturing large panels at high throughput levels. Spin coating, spray coating, meniscus coating, and extrusion coating were compared as dielectric deposition options and an in-line belt furnace was used to cure the dielectric layers on the laminate boards (rapid thermal curing). Laminate materials which were evaluated include: FR-4 (epoxy), BT (bismaleimide-triazine), PI (polyimide), and CE (cyanate ester).< >

The processing conditions for photosensitive BCB (Cyclotene** 4024-40 and Cyclotene** 4026-46) were defined for a thin film Cu/Photo-BCB MCM-D structure. Fabrication of four layer MCM-Ds, designed by Sandia National Laboratories, was demonstrated. The modules were electrically tested, solder bumped, flip chip assembled and put through a reliability test program

This work examines the planarization of polymer thin film coatings derived from Cyclotene™ 3022 prepolymer resins. Cyclotene™ 3022 is a divinyl siloxane bis-benzocyclobutene prepolymer (DVS-BCB, CAS 117732-87-3). It is used primarily as a dielectric in microelectronics applications. Using profilometry, planarization measurements have been made on thin films spun over features consisting of lines and trenches. Feature widths have been varied from 2 to 1000 μm and the feature depths and film thickness have been varied from 1 to 16 μm. Effects of the processing procedure, resin concentration and resin additives have been explored. Local (versus global) planarization will be discussed. Planarization has been found to depend on all feature dimensions and the polymer film thickness. Lines or other structures having a width of 100 μm or less can be planarized to 90% or better with standard commercial formulations of Cyclotene™ 3022, provided that the mean film thickness is twice the line-height or feature-depth. Metals such as Al, Cu, Cr and Ti can all be planarized to this degree; however, surface preparations may influence the result.

The authors demonstrate the feasibility of rapid thermal curing (RTC) of benzocyclobutene (BCB) thin films using an infrared belt furnace. The effects on film properties resulting from a dramatic reduction in cure time (5 h to 5 min) are summarized. The extent of cure was determined by FTIR (Fourier-transform infrared spectroscopy) and was subsequently modeled as a function of reaction kinetics using the measured temperature profiles. FTIR spectra from the RTC films were identical to those obtained using a conventional inert gas oven and a convectively heated belt furnace, indicating that: (1) the polymerization mechanisms and the resulting polymer network structure are identical, and (2) no chemical enhancement of the curing occurs due to the absorption of infrared radiation. There are no statistically significant differences in the resulting stress and adhesion properties for samples cured by the RTC process vs. the conventional process for film thicknesses ranging from 1 to 24 mu m. Planarization measurements, made on isolated features up to 100 mu m in width, also indicate no differences in the cured films.< >

Benzocyclobutene (BCB) is being developed to planarize both substrate glass, color filters and active devices for flat panel displays. In addition, the material is being evaluated as the alignment layer and acceptable pre-tilt angles are reported. The results of the current study have shown the BCB to exhibit superior planarization to polyimide with efficiencies 90. As an example, a typical P-V (peak-valley) of a color filter is reduced from about 1.4 (mu) initially to about 1200 angstroms with the application of 1.2 (mu) of BCB. In addition to efficiently smoothing the color filters, the BCB can also be employed to planarize the substrate glass, while acting as a Na+ barrier. For this particular example, the BCB coated glass is subjected to ITO deposition and the resultant film still exhibits excellent optical clarity with transmissions of approximately 92 respectively before and after ITO. The glass substrate is also efficiently planarized to the point that the directionality of the float direction becomes ambiguous.