A positive-tone and aqueous-base-developable benzocyclobutene (BCB)-based dielectric material curable in air is described in this paper. The prepolymer is made from divinylsiloxane bisbenzocyclobutene (DVS-bisBCB) and BCB-acrylic acid. The formulation contains antioxidants that allow the prepolymer to cure in air and a diazonaphthaquinone to make it photosensitive. Patterned films have high resolution, and via openings are scum-free without a descum operation. Whether cured in nitrogen or in air, the prepolymer produces a film with optical, electrical, thermal, and mechanical properties desirable for many microelectronic applications, such as packaging applications and as a planarization or insulation layer in display applications

14q32 translocations [t(14q)] represent critical but not universal events in multiple myeloma (MM). Gains of chromosome arms 1q, 9q, and 11q (+ 1q, + 9q, and + 11q) have recently been identified as frequent aberrations in this disease, but their pathogenetic significance remains unclear. We studied a series of 108 MM patients using fluorescence in situ hybridization and DNA probes mapping to chromosome bands 1q21, 9q34, 11q25, 13q 14, and 14q32. Three subsets of tumors were defined: (1) MM +/+ (detection of + 9q and + 11q; 43, 5% of cases), (2) MM +/- (+9q or + 11q; 21.3%), and (3) MM -/- (neither + 9q nor + 11q; 35.2%). The incidence of t(14q) was significantly different in these subgroups: 23% in MM +/+, 56% in MM +/-, and 89% in MM-/-. Deletion of 13q (13q-) also was significantly less frequent in MM+/+ (23%) than in MM+/- and MM-/(36% and 63%, respectively). The nonrandom distribution of chromosomal aberrations in the present series of MM tumors points to a novel, 14q32 translocation-independent pathogenetic pathway in plasma cell neoplasms. (C) 2004 Wiley-Liss, Inc.

The toughness of CYCLOTENE (TM) divinylsiloxane-bisbenzocyclobutene (BCB) based polymer resins from The Dow Chemical Company, is enhanced by incorporation of a second component in the polymer matrix. Thin films of modified BCB resin have significantly improved elongation at break. Excellent properties of BCB resin such as low dielectric constant and dissipation factor, low moisture up-take and higher than 350 degreesC glass transition temperature are maintained in this modified BCB material. Isothermal TGA of BCB resin with 20 wt. % additive demonstrates thermal stability of less than 1 % weight loss per hr at 325 degreesC. Residual stress of modified BCB resin thin film on a silicon wafer is about the same as BCB resin. A transmission electron micrography (TEM) study of BCB film with up to 18 wt. % of additive does not show discrete domains of the second component. At 20 % loading, some domains with approximately 0.1 mum diameter are observed. As the amount of additive increases, the size of the domains increases. Modified BCB resin formulations are photo-definable with good resolution and film retention.

With the demand for higher interconnect density increasing, the ability of polymeric insulation to resist current flow and protect circuits from corrosion is becoming more and more important. BCB polymer is being used commercially on many high density devices which must function in non-hermetic environments. It was therefore of interest to quantify the change in resistance and leakage current (under temp-humidity-bias), of BCB encapsulated circuits by conducting surface insulation resistance (SIR) and triple track testing (TTT). SIR of all the Cyclotene samples ranged from 7.5/spl times/10/sup 8/ to 8.8/spl times/10/sup 9/ /spl Omega/. TTT reveals stable resistance of all samples past 500 hours. Leakage current measurements of /spl les/4/spl times/10/sup -11/ amperes were observed. The BCB samples show results equal to or better than the Dow Corning vulcanized rubber control, indicating excellent circuit protection capability.

Multilevel high-density substrates require wirebonding to bondpads which are located over thick polymer dielectric layers. We have studied the ability to thermosonically wirebond gold onto Cu/Ni/Au surface metallurgy consisting of 2 mu m Cu representing the bondpad followed by 1 to 4 mu m electroless Ni and I pm electroless Au over 5 - 20 mu m of BCB (CYCLOTENE(TM)) dielectric. Results suggest that backcooling during sputter roughening of the BCB is important to promoting adhesion between the sputtered Ti sublayer and BCB. At BCB thicknesses of 0 to 10 mu m and any Ni thicknesses in the range elf 1 to 4 mu m, the bonds passed pull testing exhibiting a strength of 9 grams and a clean tensile failure of the bond wire. Bonding over 15 to 20 mu m of underlying BCB required higher bonding power and dwell times but reliable bonds could be made with reasonable bonding parameters if 3 or 4 mu m of Ni was present to stiffen the pad. Without sufficient Ni thickness the bondpads ripped from the substrate during bond pull testing revealing cohesive fracture damage to the BCB under the pad.

The adhesion of several underfills (Dexter Hysol FP4511, FP4527 and CNB775-34) to BCB (Cyclotene/sup TM/ 4022, 4024) has been studied through die shear testing and subsequent failure analysis. Die shear values range between 69 and 90 MPa. Failure analysis indicates that this spread in data probably results from the mixed mode nature of the fracture surfaces. From the die shear data collected before and after 24 hr water boil for Cyclotene 4022 and 4024 (with AP3000 adhesion promoter) and FP 4511 and 4527 underfillers, we find that the die shear strength decreases by an average of 11% for the 4 comparisons.

Multilevel high-density substrates require wirebonding to bondpads which are located over thick polymer dielectric layers. We have studied the ability to thermosonically wirebond gold onto Cu/Ni/Au surface metallurgy consisting of 2 mu m Cu representing the bondpad followed by I to 4 pm electroless Ni and I mu m electroless Au over 5 - 20 mu m of BCB (Cyclotene(R)) dielectric. Results suggest that backcooling during sputter roughening of the BCB is important to promoting adhesion between the sputtered Ti sublayer and BCB. At BCB thicknesses of 0 to 10 mu m and any Ni thicknesses in the range of I to 4 mu m, the bonds passed pull testing exhibiting a strength of 9 grams and a clean tensile failure of the bond wire. Bonding over 15 to 20 mu m of,underlying BCB required higher banding power and dwell times but reliable bonds could be made with reasonable bonding parameters if 3 or I mu m of Ni was present to stiffen the pad. Without sufficient Ni thickness the bondpads ripped from the substrate during bond pull testing revealing cohesive fracture damage to the BCB under the pad.

The use of a bake prior to development stabilizes the develop end point of photo-BCB films and removes the time dependence of the develop end point. The elimination of this source of process variability enables the implementation of a develop process in which, for a given film thickness and set of bake conditions, the optimum develop time is a constant, and monitoring of the end point is unnecessary.

A new structure for thin film integrated passive devices using aluminum interconnection and photo-BCB dielectrics is introduced. The structure is capable of providing a range of capacitance values spanning four orders of magnitude, making it suitable for both digital and high frequency applications. The thin films are built on glass substrates in a 350/spl times/400 mm format to take advantage of the economy of scale that comes from such a format. The structure is described and preliminary characterization and reliability test results are summarized.

Photosensitive Benzocyclobutene (Photo-BCB) has been widely reported on for use as a dielectric material in multilayer packaging applications, including: MCMs, IO redistribution, and flat panel display. Photo-BCB has many properties which are highly attractive for these applications, including: a simple processing scheme which is compatible with existing IC manufacturing techniques, low level of ionics, low moisture uptake, low cure temperatures, rapid thermal curing, high optical transparency, high planarization level, high thermal stability, high solvent resistance, very low outgassing, and a low dielectric constant.Photo-BCB is also being actively evaluated fdr wafer-level applications such as stress-buffer and passivation. In this paper, we will discuss the Photo-BCB properties and processing steps as they relate to these two applications. We will also compare the manufacturing scheme based on a one mask process for memory die, to the steps in a two mask process for stress-buffer and passivation.

Large die such as SRAMs and DRAMs are subject to significant stress resulting from thermal expansion mismatch of the die and packaging materials. The use of polymers as stress buffering media has been widely practiced to increase the reliability of these devices. Many of these devices require that small windows (/spl les/10 /spl mu/m) be opened up in the polymer over "fuse links" which are used to reroute or reconfigure inactive circuits. The need for tighter resolution in the stress buffering layer, as well as the desire for shorter process cycle times, has moved the industry from wet etch to photosensitive materials. Photosensitive BCB (Cyclotene) has been widely reported for use as a dielectric in numerous advanced packaging applications. A one mask photo-BCB stress buffer process has also been reported for opening up bond pads and fuse links in underlying SiN die passivation. Traditional passivation/stress buffer processing has required masking and dry etching of the SST followed by coating and patterning of the polymer dielectric (two mask process). The reduction in processing steps and processing time using the one mask BCB process can significantly lower the cost of ownership for passivation/stress buffer layers.

AbstractMethyl‐propiolat und ‐tetrolat (III) kondensieren mit einer Vielzahl von Olefinen in Gegenwart des Katalysators Dicarbonylcyclopentadienyl‐isobutylen‐ oder ‐THF‐Fetetrafluoroborat und bilden abhängig von der Struktur des Olefinreaktanden unterschiedliche Produkte.